Ibn Awn (may Allah have mercy on him) narrates that I wrote a letter to Nafi‘ (may Allah have mercy on him) asking about inviting the polytheists before fighting them. He replied in writing: "This practice was at the beginning of Islam, and the Prophet of Allah (peace and blessings be upon him) attacked Banu al-Mustaliq suddenly while they were unaware, and their cattle were grazing at the water. The Prophet (peace and blessings be upon him) killed their fighting men, took captives from them, and on that same day acquired Lady Juwayriya bint al-Harith (may Allah be pleased with her)." This narration was related by Sayyiduna Abdullah (may Allah be pleased with him), who was part of that expedition.