1)
What is the meaning of "Tashev Enosh Ad Daka"?
1.
Yerushalmi (Chagigah 2:1): Teshuvah is accepted even until Dichucha Shel Nefesh (he is crushed and depressed). Sha'arei Teshuvah (1:9) - however, the best Teshuvah is in his youth, when he has his strength, and he overcomes his Yetzer.
2.
Rashi: You bring afflictions on a person until he is weak and close to death.
3.
Radak: It is until he is crushed in his old age. I.e. the strength of his youth will not help him, for You will return him to be crushed.
2)
What do we learn from "[va'Tomer] Shuvu Vnei Adam"?
1.
Pesachim 54a: This teaches that Teshuvah was created before the world. It says "b'Terem Harim Yuladu
