Sahih Muslim
The Book of Zakat (Kitab Al-Zakat)
Book Number: 005 / Hadith Number: 2304
Anas b. Malik reported that when Allah conferred upon His Messenger (may peace be upon him) the riches of Hawazin (without armed encounter) ; the rest of the hadith is the same except some variation (of words):" Anas said: We could not tolerate it and he also said: The people were immature in age."