Imam Malik's Muwatta, Chapter: Sadaqa

Yahya related to me from Malik from Zayd ibn Aslam from Ata ibn Yasar that the Messenger of Allah, may Allah bless him and grant him peace, sent a gift to Umar ibn al-Khattab, and Umar returned it. The Messenger of Allah, may Allah bless him and grant him peace, said, "Why did you return it?" He said, "Messenger of Allah, didn't you tell us that it is better for us not to take anything from anyone?" The Messenger of Allah, may Allah bless him and grant him peace, said, "That is by asking. Provision which Allah gives you is different from asking." Umar ibn al-Khattab said, "By the One in whose hand my self is, I will not ask anything from anyone, and anything that comes to me without my asking for it, I will accept."