Musannaf Ibn Abi Shayba 33:1373

Ibn Numayr narrated to us, from Isma'il, from 'Amarah ibn al-Qa'qa', from Abu Zur'ah, from 'Umar ibn al-Khattab, who said: "Indeed, the most generous of people is he who is generous to one from whom he does not hope for a reward. And indeed, the most forbearing of people is he who pardons after having the power [to retaliate]. And indeed, the stingiest of people is he who is stingy with the greeting (salam). And indeed, the most incapable of people is he who is incapable in supplicating to Allah."