Sahih Muslim
The Book Pertaining to the Excellent Qualities of the Holy Prophet (may Peace be upon them) and His Companions (Kitab Al-Fadail)
Book Number: 030 / Hadith Number: 5728
Musa b. Anas reported on the authority of his father: It never happened that Allah's Messenger (may peace be upon him) was asked anything for the sake of Islam and he did not give that. There came to him a person and he gave him a large flock (of sheep and goats) and he went back to his people and said: My people, embrace Islam, for Muhammad gives so much charity as if he has no fear of want.