A man (may Allah be pleased with him) from the tribe of Juhaynah said that the Messenger of Allah (peace and blessings be upon him) said: "Perhaps you will fight a people and gain the upper hand over them, and they will protect themselves by means of their wealth and children."
Sa'id said in his narration: "They will make peace with you," and then both agree on: "Do not take anything from them beyond that, for it is not for you."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجزية / 18730