Abu Dawud
Tributes, Spoils And Rulership
Book Number: 013 / Hadith Number: 3045
Narated By A man of Juhaynah : The Prophet (pbuh) said: Probably you will fight with a people, you will dominate them, and they will save themselves and their children by their property. The version of Sa'id has You will then conclude peace with them. The agreed version goes: Then do no take anything from them more than that, for it is not proper for you.