Abu Dawud
Zakat
Book Number: 003 / Hadith Number: 1687
Narated By AbuHurayrah : The Prophet (pbuh) commanded to give sadaqah. A man said: Apostle of Allah, I have a dinar. He said: Spend it on yourself. He again said: I have another. He said: Spend it on your children. He again said: I have another. He said: Spend it on your wife. He again said: I have another. He said: Spend it on your servant. He finally said: I have another. He replied: You know best (what to do with it).