Genesis Rabbah 49, 9

R. Levi commented: Shall not the judge of all the earth do justly? If You desire the world to endure, there can be no absolutely strict judgment, while if You desire absolutely strict judgment, the world cannot endure, yet You would hold the cord by both ends, desiring both the world and absolute judgment! Unless You forgo a little, the world cannot endure. Said the Holy One, blessed be He, to Abraham: ‘You have loved righteousness’ (Psalms 45:8): you have loved to justify My creatures; ‘and hated wickedness’: you have refused to condemn them. ‘Therefore God, your God, has anointed you with the oil of gladness above your fellows.’ From Noah to you there were ten generations, and out of all of them I remembered you alone. [Translation by Soncino, modified for modernity of language]