תּלמוד אויף ויקרא 26:42

⁶²Lev. rabba 36(3). Another explanation: Hand to hand will not cleanse evil. Rebbi Phineas said, that is one who gives alms and expects an immediate reward. Rebbi Simon said, like a man who says, here is a sack, here is a tetradrachma, and here is a se`ah, go and fill it. You should know that this is so, for if the patriarchs had demanded to receive the reward in this world for the good deeds which they did, from where would their merit remain for their descendants after them? That is what Moses told Israel⁶³Lev. 26:42.: I shall remember My covenant with Jacob, etc.