The Purpose of Exile: To Ensure Jewish Survival

The Midrash

“If Esau comes to one camp and smites it” – this refers to our brethren in the south – “the remaining camp will escape” – this refers to our brethren in Babylon.
(Genesis Rabbah 76:3)

Nachmanides, known as Ramban, Biblical and Talmudic commentator (1194-1270)
G-d in His mercy will remember that they were always His people, and that they were His servants, who loyally tolerated the afflications and oppression of exile.
(Deuteronomy 32:26)

All the curses in the Torah applied only before we went into exile. But after we were in exile in the lands of our enemies, the works of our hands were not cursed, nor our cattle and sheep, nor our vineyards and olive trees and what we plant in the field. Rather, we will live on a similar level to the nations among whom we live, or even better than them, since His mercy is upon us, because our dwelling in exile comes with the promise
(Leviticus 26:44),

” And even so, when they are in the land of their enemies, I did not reject them nor despise them, to destroy them, to annul My covenant with them.”
(Commentary on Deuteronomy 28:42)

Rabbi David Shlomo Eibeschitz, Rabbi of Soroki, Bessarabia (1755-1813)
Since G-d knows that the Jewish people needs to be in exile for their own good, He decreed that they should not force the end of exile.
(Arvei Nachal, Parshas Bo)

Rabbi Bachya ben Asher, Spanish Biblical commentator (1255-1340)
If the redemption is delayed, it is for the purpose of adding to our eventual reward and adding punishment to those who afflicted us.
(Commentary on Exodus 5:22)