If you find that somebody is not grateful for all that you have done for him, then do not get disappointed because often you will find that someone else feels under your obligation though you have done nothing for him and thus your good deeds will be compensated, and Allah will reward you for your goodness.
Ali ibn Abi TalibIf you are greeted then return the greetings more warmly. If you are favored, then repay the obligation manifold; but he who takes the initiative will always excel in merit.
Ali ibn Abi Talib