Tao Te Ching · Ch. 79

和大怨,必有餘怨;安可以為善?是以聖人執左契,而不責於人。有德司契,無德司徹。天道無親,常與善人。

Hé dà yuàn, bì yǒu yú yuàn; Ān kě yǐ wéi shàn? Shì yǐ shèng rén zhí zuǒ qì, ér bù zé yú rén. Yǒu dé sī qì, wú dé sī chè. Tiān dào wú qīn, cháng yǔ shàn rén.

After a great grievance is settled, some resentment will surely remain — how can this be considered good? Therefore the sage holds the left side of the contract and does not demand repayment from others. One who has virtue attends to the obligations of the contract; one who has no virtue attends only to collecting what is owed. The way of Heaven has no favourites — it is always with the good person.

— Tao Te Ching 79

Source: Wang Bi edition (Chinese) + Hanyu Pinyin transliteration