The Duties of the Heart, by Rabbi Bachye, tr. by Edwin Collins, , at sacred-texts.com
All admit that our obligation to benefactors is in proportion to their intention to benefit us, and that even if, through some accident or hindrance, their deeds fall short of their goodwill, and they fail to do us good; . . . while, on the other hand, we owe no debt of gratitude to those by whose acts we are benefited without their intending to do us good. It will now be shown that while in almost all the motives to human benevolence self-interest plays a part, the benevolence of God is entirely disinterested.