Originally published in Zvia Ginor, ed., Yakar Le’Mordechai: Jubilee Volume in Honour of Rabbi Mordecai Waxman. Essays on Jewish Thought, American Judaism, and Jewish-Christian Relations (Ktav Publishing House, Inc.: Temple Israel of Great Neck, NY 1998)
In yeshiva circles they say: ‘One does not die because one has a difficulty in a given text.’ The source of this saying is the account of R. Hayim of Volozhyn in a case concerning an agunah who was allowed to marry. A number of rabbis, basing their pilpul on a difficult question (kushya), declared that the woman was allowed to remarry because her husband had died. R. Hayim, after hearing the argument, commented: ‘aber fun a kushya starbt man nit,’ i.e. the man cannot be declared dead solely on the strength of a kushya.  Kaplan quotes this story in the name of R. Joseph Zechariah Stern of Shavul. Dov Eliach quotes the end of the story.  The supposedly dead husband eventually turned up, whereupon R. Hayim declared: ‘The pilpulim were ingenious yet a simple man [the husband] came along and refuted them on the spot.’ R. Haim’s saying, as it travelled from mouth to mouth in the yeshivas, came to mean that one should not despair if one has a difficulty. One can live with a kushya, i.e. the student of the Torah should continue with his studies even if he cannot find the solution to a knotty problem.
In a different vein, the following story is told of R. Eizel Shapiro of Slonim, a renowned nineteenth-century Lithuanian rabbi.  Reb Eizel, while on a visit to Volozhyn, set a halakhic problem to the students, declaring that the student who solved it would be worthy to become his son-in-law. During Reb Eizel’s stay the most brilliant students came to his door with the conjectured solution but were dismissed one by one. Just as Reb Eizel was mounting his carriage to be on his way, a student came running and called on Reb Eizel to stop. ‘Ah,’ said Reb Eizel, ‘you found the correct solution.’ ‘No,’ replied the student, ‘but, please Rebbe, before you leave, I beg you, tell me the solution.’ Reb Eizel replied, ‘You’re the one!’
Stories such as these underline the virtue of admitting ignorance when no answer is available. This principle is exemplified by Rashi (1040-1105), the notable medieval scholar who wrote invaluable commentaries on the Bible and the Talmud. Rashi, commenting on a ruling by R. Simeon ben Eleazar in tractate Berakhot of the Babylonian Talmud (25b), states that he is unable to locate the source of this reference. R. Akiva Eger (1761-1837), in his Gilyon Hashas, gives a list of almost forty places in Rashi’s commentary on the Talmud where Rashi similarly confesses his ignorance. Moreover, R. Akiva Eger, inGilyon Hashas on tractate Shabbat 118b, gives a short list of places where the Tosafists also declare that they ‘do not know’. There are numerous instances in which the Tosafists raise a question without providing the answer, but evidently R. Akiva Eger only wished to list those instances in which the Tosafists actually use the words ‘do not know’. R. Joseph Engel (1859-1920), in his Gilyonei Hashas on Berakhot 25b, adds a number of further items to the list compiled by Eger. He further states that R. Akiva Eger was anticipated by R. Jair Hayim Bacharach (1638-1702). In his responsa Hut Hashani, no. 19, Bacharach lists a number of places in which the Tosafists respond to Rashi’s confession of ignorance. R. Jacob Kanievsky, known as The Steipoler (d. 1985), in his works Gilyonot Kehillot Ya’akov (on Berakhot 25b) adds many further items, including Rashi’s comment on the verse: ‘And again the anger of the Lord was kindled against Israel’ (2 Samuel 24: 1), upon which Rashi comments: ‘I do not know why.’
R. S. Winograd, in ‘The Notes of Rabbi Akiba Eiger to Berachoth 25b’  refers to other authors who have provided a list of places in which Rashi declares his ignorance. Hayim Hezekiah Medini (1832-1904), in his Sedei Hemed, also adds sixty items of his own from Rashi’s commentary on the Bible and 105 items from Rashi’s commentary on the Talmud over and above the lists of his predecessors.  Medini examines the question of Rashi’s motives in giving expression to his ignorance. He notes that Raphael Solomon Laniado (d. 1793) refused to accept the idea that Rashi is hinting at hidden meanings as some have done. It is simply that, as the tanna says in tractate Avot, it is the mark of a wise man who does not know something to admit that he does not know it. He might have quoted the saying in tractate Berakhot 4a: ‘Teach thy tongue to say: “I do not know” lest thou be led to falsehoods and be caught out.’ Laniado writes somewhat naively:
‘It seems obvious to me that he [Rashi] had no deep intentions but simply wished to carry out the advice of the tanna not to say “I know” when one does not know. He [Rashi] wished to inform others of his distress so that they should put their minds to understand the matter since in his humility and righteousness he said to himself that if he does not know others may well known the answer.’
In addition, Medini refers to R. Malachi ben Jacob Hakohen (d. 1785-1790), who quotes a number of other early commentators also admitting to their ignorance. 
Anyone familiar with Rashi’s methodology is aware that Rashi has an uncanny knack of anticipating the students’ questions and simply supplies the answers. When Rashi cannot supply the answer, his integrity will not allow him to pass over the matter in silence. Consequently, Rashi is obliged to say to students of the text: Do not torment yourself at your failure to grasp the meaning since there is a real difficulty in this text to which I, unfortunately, cannot supply the answer. Rashi’s admission of ignorance is in itself a kind of comment on the difficult text. Contrary to Laniado, Rashi is not seeking others to find the answers without trying to discover one himself. It is not Rashi’s humility that compels him to admit ignorance, but his scholarly integrity. He is, in fact, warning the student that the difficulty here is real and no amount of sophisticated casuistry can hope to solve it.
Rashi’s comment on Exodus 26: 4 is germane to this issue. He writes on the Ephod:
‘I have heard no tradition, nor have I found in a Baraita any description of its form but my own mind tells me that it was tied on behind; its breadth was the same as the breadth of a man’s back; like a kind of apron which is called pourcient in French which ladies of rank tie on when they ride on horseback.’
Thus Rashi is not averse to a degree of guesswork where the answer seems plausible. However, in the majority of cases cited by R. Akiva Eger and the others, Rashi cannot provide a solution even by guessing. For instance, when the Talmud refers to the ruling of R. Simeon ben Eleazar (see above), the talmudic source is known but not supplied. Rashi, with his vast knowledge of the Talmud, cannot find it anywhere and is forced to say that he cannot locate the source. Guessing can hardly have been of any use here.
What motive did R. Akiva and the others have in listing Rashi’s admissions of ignorance? It would seem that they believed it essential to point out that even a great teacher like Rashi could remain ignorant in certain matters. The implication is that every good teacher or commentator will understand that this is part of his task: to admit when he does not have an answer and then press on.
- See Zevi Kaplan, Me’olamo shel Torah (Jerusalem, 1974), p. 79.
- Avi Hayeshivot, vol. 2 (Jerusalem, 1991), p. 395.
- This story is also well known, see Yasiel Meltzer, Bederekh Etz Hahayim (Jerusalem, 1986), pp. 510-11.
- Hadarom, no. 30 (Tishri 5730), pp. 121-8.
- Hayim Hezekia Medini [ed. Friedman], Kelalei Haposekim, vol. 9, no. 8 (New York: 1962), p. 143, gives his own list and refers to R. Raphael Solomon Laniado (d. 1793) who, in his Hama’alot Lishlomoh (Constantinople, 1775), pp. 90-1, lists items from Rashi’s commentary on the Bible.
- Yad Malakhi, no. 246 (Jerusalem, 1976), pp. 53b-54a. Actually, all the sources quoted by Malakhi Hakohen are not simply admissions of ignorance but are alluding to references unknown by the authors.