Ha'azinu: Chapter 53
"And yet for all that, when they are in the land of their enemies" - "Do you thus requite Hashem"

Rabbi Aba says that even though Yisrael sinned and went into exile, God and His Shechinah are always with them. Rabbi Yehuda wonders how Yisrael could repay God for His goodness by sinning and thus sending the Shechinah into exile.