Oid Yenuvun B'Seiva

Rabbi Yishmael son of Rabbi Yosei says: (Study Torah in your old age.) If you studied Torah in your youth, do not say: I don’t have to study in my old age. Rather, study Torah, for you do not know which [period of study] will be most beneficial. If you studied Torah at a time of wealth, do not turn away from it at time of poverty. If you studied Torah at a time of satiation, do not turn away from it at a time of hunger. If you studied Torah at a time of leisure, do not turn away from it at a time of stress. For it is better for a person to have one thing during a crisis than a hundred in the midst of abundance (as it says, “For you do not know if they will both be equally good”), as it says, (Ecclesiastes 11:6), “Sow your seed in the morning, and do not hold back your hand in the evening.”
Rabbi Akiva says: If you studied Torah in your youth (study Torah in your old age), do not say: I don’t have to study in my old age; for you do not know which will be the most beneficial, if both will stay with you, or if both will be equally good, as it says, “Sow your seed in the morning.”
Rabbi Meir says: If you studied with one teacher, do not say: That’s enough for me. Rather, go to another sage and study Torah. But do not go to just anyone. Rather, go to someone who has been close to you from the start, as it says (Proverbs 5:15), “Drink water from your own cistern, that which flows from your own well.”
Every person has an obligation to apprentice with three Torah scholars, such as Rabbi Eliezer, Rabbi Yehoshua, and Rabbi Akiva, as it says (Proverbs 8:34), “Happy is the person who hears me come early to my doors every day, and waits outside my opening.” Do not read it as “doors,” but “a door and two doors” [a total of three], for you do not know if two of them will work for you, or if two of them will be equally good, as it says (Ecclesiastes 11:6), “Sow your seed in the morning.”
Rabbi Yehoshua says: Marry a woman in your youth, and marry a woman in your old age. Have children in your youth, and have children in your old age. Do not say: I will not marry a woman. Rather, marry a woman and have sons and daughters, and be fruitful and multiply greatly in the world. For you do not know if both of them will work out for you, or if both of them will be equally good, as it says (Ecclesiastes 11:6), “Sow your seed in the morning.”

I will praise the LORD all my life,
sing hymns to my God while I exist.

Let all that breathes praise the LORD.
Hallelujah.

The Gemara cites another derivation connected to child-rearing: “Therefore, so says the Lord to the house of Jacob, who redeemed Abraham; Jacob shall not now be ashamed, neither shall his face now wax pale” (Isaiah 29:22). But where have we found any indication about Jacob that he redeemed Abraham? Rav Yehuda says: It means that he redeemed him from the suffering of raising children, in that Abraham did not have twelve tribes and the resultant hardships involved in raising them, as Jacob did, as Jacob assumed the burden of raising the tribes of Israel. And this is as it is written: “Jacob shall not now be ashamed, neither shall his face now wax pale,” meaning: “Jacob shall not now be ashamed” before his father, and “neither shall his face now wax pale” before his father’s father, since he took upon himself the role that they bore as well.

Do not cast me off in old age;
when my strength fails, do not forsake me!

You shall rise before the aged and show deference to the old; you shall fear your God: I am the LORD.

Rabbi Akiva says that the verse should be understood as follows: If one studied Torah in his youth he should study more Torah in his old age; if he had students in his youth he should have additional students in his old age, as it is stated: “In the morning sow your seed, etc.” They said by way of example that Rabbi Akiva had twelve thousand pairs of students in an area of land that stretched from Gevat to Antipatris in Judea, and they all died in one period of time, because they did not treat each other with respect.