מדרש על בראשית 43:14

And God Almighty give you mercy before the man (Gen. 43:14). May it please our master to teach us the number of times a man must pray each day. Thus did our masters teach us: A man must not pray more than three times each day, as instituted by the patriarchs of the world. Abraham established the morning prayer, as it is said: And Abraham got up early in the morning to the place where he had stood before the Lord (Gen. 19:27). The word stood refers only to prayer, as is said: Then stood up Phinehas, and prayed (Ps. 106:30). Isaac instituted the afternoon prayer, as it is said: And Isaac went out to meditate in the field (Gen. 24:63). The word meditation is used with reference to prayer, as it is said: A prayer of the afflicted when he fainteth, and poureth out his meditation for the Lord (Ps. 102:6). Jacob introduced the evening prayer, as it is said: And he lighted upon the place (Gen. 28:11). The word vayifgah (“lighted upon”) alludes to prayer, as is said: Therefore, pray not thou … neither make intercession (tifga) (Jer. 7:16). And it is written concerning Daniel: And he kneeled upon his knees three times a day, and prayed (Dan. 6:11). However, in this verse, the time of prayer is not specified. It was David who came and set the time for prayer, by saying; Evening, and morning, and at noonday, will I complain and moan, and He hath heard my voice (Ps. 55:18). Therefore a man may not pray more than three times a day.

It is essential that a man rise early to pray, for there is nothing more powerful than prayer. A proof of this is that though at first it was decreed that Moses was not to enter or even see the Holy Land, yet because he prayed for a long time, it is written concerning him: The Lord showed him all the Land (Deut. 34:1). Similarly, because Hezekiah prayed, the decree against him was abrogated.⁹Hezekiah averted a decree of death for his failure to marry and beget children by reciting prayers (see II Kings 20:1–7, Isa. 38:1–8). And Jacob also prayed for his sons when he sent them to Egypt, as it is said:; And God Almighty give you mercy (Gen. 43:14).

And God almighty give you mercy before the man (Gen. 43:14). Scripture states elsewhere in allusion to this verse: For this let everyone that is godly pray unto Thee in a time when Thou mayest be found (Ps. 32:6). R. Abba maintained: In a time when Thou mayest be found refers to old age. It is essential that a man pray for an old age in which his eyes may see, his mouth may eat, and his feet may walk. Normally, when a man becomes old, his faculties leave him. For example, it is written about Isaac: And it came to pass, that when Isaac was old, and his eyes were dim, so that he could not see (Gen. 27:1). And concerning Jacob, Scripture states: Now the eyes of Israel were dim for age, so that he could not see (Gen. 48:10). As to a mouth that could not eat, we find that Barzillai said to David: Can thy servant taste what I eat or what I drink? Can I hear anymore the voice of singing men and singing women? Therefore, then, should thy servant be a burden unto my lord the king? (II Sam. 19:35).