At twenty pursue the study of the law.
Avoth, chap. 5.
Rabbi Yehudah says the early Pietists used to suffer some twenty days before death from diarrhoea, the effect of which was to purge and purify them for the world to come; for it is said, "As the fining pot for silver, and the furnace for gold, so is a man to his praise" (Prov. xxvii. 21).
Semachoth, chap. 3, mish. 10.
It may not be out of place to append two or three parallel passages here by way of illustration:—"Bodily suffering purges away sin" (Berachoth, fol. 5, col. 1). "He who suffers will not see hell" (Eiruvin, fol. 41, col. 2). "To die of diarrhoea is an augury for good, for most of the righteous die of that ailment" (Kethuboth, fol. 103, col. 2, and elsewhere).
The bathing season at (the hot baths of) Dimsis lasted twenty-one days.
Shabbath, fol. 147, col. 2.
A fowl hatches in twenty-one days, and the almond tree ripens its fruit in twenty-one days.
Bechoroth, fol. 8, col. 1.
Rabbi Levi says the realization of a good dream may be hopefully expected for twenty-two years; for it is written (Gen. xxxvii. 2), "These are the generations of Jacob, Joseph being seventeen years old when he had the dreams." And it is written also (Gen. xli. 46), "And Joseph was thirty years old when he stood before Pharaoh," etc. From seventeen to thirty are thirteen, to which add the seven years of plenty and the two years of famine, which make the sum total of twenty-two.