Sahih Muslim Book 20, Hadith Number 4601.

Chapter : No migration after the conquest of Mecca but allegiance could be sworn (to a rightful leader) on serving the cause of Islam, on fighting in the way of Allah and on following the path of virtue.

This tradition has been handed down through a different chain of transmitter with the addition of the following words at the end: “Do you milk them on the day they arrive at the water? He replied: Yes.”