Abu Dawud Book 13, Hadith Number 3061.
Narated By Sakhr ibn al-Ayla al-Ahmasi : The Apostle of Allah (PBUH) raided Thaqif. When Sakhr heard this, he proceeded on his horse along with some horsemen to support the Prophet (PBUH). He found the Prophet of Allah (PBUH) had returned and he did not conquer (Ta’if).
On that day Sakhr made a covenant with Allah and had His protection that he would not depart from that fortress until they (the inhabitants) surrendered to the command of the Apostle of Allah (PBUH). He did not leave them until they had surrendered to the command of the Apostle of Allah (PBUH).
Sakhr then wrote to him: To proceed: Thaqif have surrendered to your command, Apostle of Allah, and I am on my way to them. They have horses with them.
The Apostle of Allah (PBUH) then ordered prayers to be offered in congregation. He then prayed for Ahmas ten times: O Allah, send blessings the horses and the men of Ahmas.
The people came and Mughirah ibn Shu’bah said to him: Prophet of Allah, Sakhr took my paternal aunt while she embraced Islam like other Muslims.
He called him and said: Sakhr, when people embrace Islam, they have security of their blood and property. Give back to Mughirah his paternal aunt.
So he returned his aunt to him and asked the Prophet of Allah (PBUH): What about Banu Sulaym who have run away for (fear of) Islam and left that water? He said: Prophet of Allah, allow me and my people to settle there.
He said: Yes. So he allowed him to settle there. Banu Sulaym then embraced Islam, and they came to Sakhr. They asked him to return their water to them. But he refused.
So they came to the Prophet (PBUH) and said: Prophet of Allah, we embraced Islam and came to Sakhr so that he might return our water to us. But he has refused.
He (the Prophet) then came to him and said: When people embrace Islam, they secure their properties and blood. Return to the people their water.
He said: Yes, Prophet of Allah. I saw that the face of the Apostle of Allah (PBUH) was reddening at that moment, being ashamed of taking back from him the slave-girl and the water.