It is narrated from Sayyiduna Rafi' bin Makith (may Allah be pleased with him) - and he was among those present at al-Hudaybiyah - that the Prophet (peace and blessings be upon him) said: "Good treatment (of those under one's authority) is a source of blessing, bad character is a source of ill fortune, righteousness is a means of increase in lifespan, and charity protects against an evil death."
Hadith Referenceالمعجم الكبير للطبراني / باب الراء / 4436