By Ezra Brand
Some time ago there was a discussion in cyberspace regarding whether the Avos kept all of the mitzvos. The discussion was started when a video on Youtube made fun of the idea, and a response to the video was published on the Hirhurim blog (here), as well as counter-response (here). I'd like to discuss some of the basic issues involved.
The Mishnah at the end of Kiddushin says that Avraham kept the whole Torah. The Rambam (Hil. Melachim 9:1) brings down the mitzvos that each of the Avos innovated. Many laws are learned from the stories in Bereishis even though they happened before the giving of the Torah.
However, Chazal do not discuss any of the questions arising from the statement that the Avos “kept the Torah.” Here and there, the commentators discussed some of the more obvious questions. For example, the Ramban in his commentary on the Torah (Gen. 26:5) famously asks how Ya'akov could have married two sisters, something prohibited by the Torah. This question in particular seemed to have intrigued many commentators.
The later commentators discussed whether the Avos and their children had the status of Jews or non-Jews, since they lived before Matan Torah. This question is discussed extensively by the author of the Mishneh L'melech in his sefer P'rashas D'rachim. Later, this was discussed at length by R' Yosef Engel in the first volume of the encyclopedia he started to write, called Beis Ha'otzar, under the entry “Avos.” An interesting question that was first posed by R' Pinchas Horowitz, one of the rebbeim of the Chasam Sofer, in his commentary on the Torah, Panim Yafos, is the following: According to the opinion that the Avos were inherently non-Jews, how could they keep the whole Torah, which includes keeping Shabbos? We know that a non-Jew is prohibited from keeping Shabbos, so what did they do? Many ingenious answers are given to this question.
A few hundred years ago, a popular method of learning was the “pilpul” method. In short, this method consisted of explaining difficult passages in the Gemara by connecting the passage under discussion with other seemingly unconnected passages of Gemara in other places. This style was not limited to Gemara, but was also used when explaining the Chumash. This method was attacked by R' Yair Chaim Bachrach, author of the Chavos Yair, as well as by others. In any case, in these seforim pilpul was used to answer questions on the Avos's actions. To quote the Encyclopedia Judaica (1st edition, Volume 13, entry “Pilpul,” pg. 527): “Criticism was much more lenient regarding the application of pilpul to the exposition of the Bible and the homiletic literature, since this was considered irrelevant to a true understanding of halakhah. Consequentially, popular preachers used to strain their imagination by adducing the most complicated talmudic passages and controversies in order to throw new light on a story from the Bible or the Midrash.”
In the past 150 years, literature on the attempted synthesis of the Torah Shebichsav (Written Torah) and the Torah Shebal Peh (Oral Torah) has exploded. This literature was meant to show that the explanations of Chazal, Torah Shebaal Peh, are in truth hinted to in the Torah Shebichsav itself. Originally, the reason for this was the attacks of the maskilim on the tradition of Torah Shebaal Peh. This led to the commentaries of R' Shamshon Rephael Hirsch, the Malbim, the sefer Haksav V'Hakabbalah, and the sefer Meshech Chochma. In addition, many anthologies of the words of Chazal regarding the written Torah were collected and put in the order of the Torah. Examples of this include the sefer Torah Temimah, as well as the still-incomplete Torah Shleimah. 
However, these commentaries, in their comments on Sefer Bereishis, do not systematically try to harmonize the actions of the Avos with the accepted halachah. This is somewhat surprising, since the point of their commentaries is to harmonize the Torah Shebichsav with the Torah Shebaal Peh, and this would seem to be a part of that job description.
With the contemporary stress in the yeshivos on the learning of Gemara to the exclusion of almost everything else (excluding perhaps mussar seforim), and the great stress on “lomdus”, some recent seforim have followed the trend of harmonizing Torah Shebichsav with Torah Shebaal Peh to the extreme. (Lomdus is an expression used in yeshivos to refer to the Brisk analytic-style of identifying and analyzing concepts. The Yiddish term reid is also used to mean the same thing.) These modern seforim will treat the possuk like a piece of Gemara, ignoring possible theological or philological explanations, and only answer using lomdus. This lomdus can be taken to such extremes that it is often very similar to the pilpul commentaries on the Torah of the 17th century. These seforim basically spend a long time trying to answer a question in any possible way, without trying to actually fit the explanation into the passuk in any way.
The sefer Chavatzeles Hasharon by R' Mordechai Carlebach (on Bereishis, Yerushalayim 5765) is the most popular of this genre. This sefer essentially contains essays of lomdus based on the parshah, including many questions on the halachic acceptability of the Avos's actions. Even more recently, the sefer Arugas Habosem by R' Menachem Ben Yakov (on Bereishis and Shemos, Yerushalayim 5772) is almost an exact copy of Chavatzeles Hasharon, not only in content but also in the physical layout. A sefer by a nephew of R' Shlomo Zalman Auerbach, R' Baruch Rakovski, called Birchas Avos (Yerushalayim 5750), is completely devoted to questions on the Avos's actions, as is the sefer Mili D'Avos (by R' Shmuel Yaffah, Lakewood 5770).
Recently, seforim which collect divrei torah on the parshah from different sources have gained popularity. One of the first of this genre is the Pardes Yosef (by R' Yosef Pazanavski, incomplete, Bereishis, Piotrkow 5690, Shmos and Vayikra, Lodz 5697). This was followed many years later by R' Yisachar Rubin's very popular Talelei Oros (10 volumes, Bnei Brak 5753-5757). Another sefer of this genre is K'motzei Shallal Rav, which collects divrei torah on the parshah from places one would normally not expect to find them, such as in introductions to a halachic works. Since these divrei torah are in the context of a halachic work, many times they are very halachically oriented. Hence, these divrei torah also fall into the category of trying to synthesize. Pilpula Charifta, by R' Natan Margolis (on Bereshis, volume 1, Yerushalayim 5755, volume 2, Yerushalayim 5750), also collects divrei torah in the same manner.
Are these kinds of explanations part of the “Seventy Faces of Torah”? Do the authors of these explanations themselves think there is any truth to the explanations they are presenting? The author of the Klei Chemda writes in his introduction that much of what he wrote in the sefer is "לחדודי בעלמא”, to sharpen the mind. This idea comes from the Gemara, which says that sometimes teachers who say a false din in order to get their students thinking, and ultimately to correct them.
I think that a similar question has to be asked on many Chassidic explanations, as well as the common “vort.” Did the authors of these explanations really think this was a possible explanation of the text? I think not. In fact, many times authors will write that their explanation is “בדרך צחות". So why do they bother writing them? There are two possible explanations. First of all, even if the explanation is not true, the parts leading up to it are. (Assuming there is more than one part to the explanation.) The vort is a fun way to teach people the intermediate parts. In addition, they will be able to remember the intermediate parts more easily, since they are logically connected to an interesting end. A second possible explanation for why the authors wrote such explanations is that there is an underlying moral message (assuming there is an underlying moral message). As with the first explanation, the vort is an enjoyable, and therefore effective, way of getting across a moral lesson.
Would a Chassidic Rebbe admit that his “Toyreh” is not the true explanation of the verse? That is a question that I cannot answer.
 also Yoma 28b; Yerushalmi Kiddushin Perek 2 Halacha 12; Vayikra Rabbah 50:10; Tanchuma Lech L'cha 11; and many more places. See Encylopedia Talmudit, Volume 1, entry "אבות”, pg. 36-37.
 See Encylopedia Talmudit, Volume 1, entry “אין למדין מקודם מתן תורה”, pg. 635ff. However, see the Encyclopedia Talmudit ibid. that quotes the Yerushalmi that says that we don't learn laws from stories of events that happened before the giving of the Torah. See Encyclopedia Talmudit ibid. for various attempted explanations.
 See Sanhedrin 58b where the Gemara discusses some of the marriages of the Avos in the context of discussing the laws of incest for b'nei no'ach. However, the laws of b'nei no'ach are far less than what a Jew must keep. The Gemara in Yoma (referenced in note 1) says that Avraham even kept rabbinically mandated laws.
 Regarding all this see Encyclopedia Talmudit referenced in note 1. See also Maharatz Chayes in Toras Hanevi'im, Chapter 11, pg. 63-72; Nefesh Hachaim, Sha'ar 1, Chapter 21; Leket Yosef (available here); Steven Wilf, The Law Before The Law, Lexington Books, 2008 (here).
 R' Bachrach attacked the pilpul method in Shu”t Chavos Ya'ir, siman 123, and at length in an unpublished sefer of his called Ya'ir Nesiv. Parts of it were published by Jellenik in the journal Bikurim, Vienna 5624, pg. 4. Pilpul was also attacked by the Maharal and the Shelah. See also the ostensibly anonymous K'sav Yosher, published in 5544, pg. 9b, (here). It's author was Saul Berlin of Besomim Rosh infamy.
 I'd like to point out at this point that much of what I will write also applies to the Jews after matan torah. There are many questions on how their actions fit with the commonly accepted halacha. However, I am mainly focusing here on the actions of the Avos. As for the actions of the Bnei Yisroel after matan torah, the Gemara discusses these questions in many places. Many times the answer of the Gemara is that the action was a hora'as sha'ah, i.e. a temporary waiver of the prohibition. See at length Encyclopedia Talmudit, Volume 8, entry “הוראת שעה”. R' Yitzchok Halevy in his monumental Doros Harishonim, in the volume discussing Tanach and aimed at refuting the Bible Critics, tries to answer many of the questions of the maskilim on the Torah Shebaal Peh based on Tanach. Another sefer that I am aware of that discusses these questions is the commentary Mussar Hanevi'im, on Nevi'im Rishonim (by R' Yehuda Leib Ginzburg, Volume 1, St. Louis 5705, Volume 2, Yerushalayim 5736, available here and here).
 Interestingly, a hundred years before the publishing of the Torah Temimah, R' Dov Ber Treves, who was on the beis din of Vilna at the time of the Gra, also wrote a commentary on the Torah bringing down many of the saying of the Gemara in order of the Torah. In fact, the Torah Temimah was accused of plagiarizing from the Revid Hazahav. Another little known work of this sort is the Be'er Heiteiv (Vayikra, Vilna 5627), available here. The Chazon Ish writes on this workוראיתי להגאון האדיר ר' אריה ממינסק בספרו באר היטב... (חזון איש, קדשים ס' כו אות טז).
 They do, however, discuss these questions in many places, especially the Meshech Chochma. The Netziv in his commentary on the Torah, Ha'amek Davar, also incorporates much from Torah Sheba'al Peh, and answers questions on the Avos's actions.
 There is a similar phenomenon of seforim collecting the different explanations of the commentators on the Talmud, such as Machon Yerushalayim's Otzar Mefarshei HaTalmud, Frankel's Mafte'ach, and many others.
 For a description of the Pardes Yosef, see an earlier post on the Seforim Blog here.
 Eiruvin 13a, and other places. This is one of the contexts in which it is permitted to lie. See R' Yosef Chaim, Shu"t Torah Lishmah, siman 364, Yerushalayim 5736, pg. 250 s.v. ובגמרא דעירובין. R' Yosef Chaim in that response collects all the places in which it is permitted to lie. Contrary to popular belief, it permitted to lie in far more than the three places the Gemara in Bava Metzia 23b says. One of the most surprising cases in which it is permitted to lie, is the following: If a person knows that a certain halacha is true, but because of his low standing in people's eyes, when he says it, it will not be accepted, he is permitted to say that a certain gadol said that halacha, even if that gadol never said such a thing! See at least four examples of this in Torah Lishmah there (pg. 250, s.v. ובגמרא דשבת; ibid. s.v. עוד שם בדף נא; pg. 251. s.v. ובגמרא דפסחים; pg. 252, s.v. עוד שם בדף כ. This would seem to cause problems for the mesorah of Torah Shebaal Peh, and was in fact one of the maskilim's questions on the veracity of the mesorah. See I.H. Weiss, Dor Dor V'Dorshov, Part 1, Chapter 1, pg. 4.
 This is similar to what the Rambam writes in the introduction to his Peirush Hamishnah (Mossad HaRav Kook edition pg. 10) regarding asmachtos. He writes that the Gemara never intended to to say that asmachtos are true explanations of the verse. Rather, the asmachta is a formula to help people remember the halacha, as in the times of Chazal it was prohibited to write Torah Shebaal Peh. This view is atacked harshly by the Ritva, Rosh Hashonoh 17a. See Encyclopedia Talmudit, Volume 2, entry "אסמכתא”, pg. 106, footnote 16 and 28.
 A possible nafkah minah (halachic ramification) is whether it is permitted to learn the explanation in the bathroom, where learning Torah is generally prohibited. However, this nafkah minah is mostly theoretical, because, as was pointed out, even if the explanation itself is not true, many times the constituent steps are Torah. See Yisroel Bazenson, Messilat Hak'sharim (Tel Aviv 5766), (this sefer is written by a follower of Breslov and attempts to formulate “rules” for learning Likutei Moharan) pg. 153, where the author asks this question regarding the teachings of R' Nachman of Breslov; he points out that many times R' Nachman's explanations even go so far as to contradict the simple meaning of the phrase he is coming to explain. Bazenson answers:
ברוב הפסוקים ומאמרי חז"ל שהוא שהוא מפרש על פי דרכו הפנימית , לאף שנראה כמשנה או אפילו כסותר הפירוש הרגיל , אם יזגה המעיין ישיג את המקום שבו שני הפירושים מתחברים ועולים בקנה אחד. ואז הפירוש הרגיל יקבל, כתוצאה מחיבור זה, תוספת בהירות שמעולם לא היתה לו.
Bazenson then goes on to bring three examples of such places in Likutei Moharan, and attempts to show how in fact the nistar complements the nigleh. (I would like to thank Eliezer Shore for pointing out this source to me.) I have not studied his explanations in depth to see if they are convincing.