It is narrated from Sayyiduna Hakim bin Hizam (may Allah be pleased with him) that he asked the Prophet (peace and blessings be upon him): Which charity is best? He (peace and blessings be upon him) said: "Begin with those who are under your care, and the best charity is that which is given while one remains well-off."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 3116