Sayyiduna Jarir (may Allah be pleased with him) said: the Messenger of Allah (peace and blessings be upon him) sent an army to Khath'am. When the horsemen came upon them, they tried to seek protection by praying, yet one man among them was killed. The Messenger of Allah (peace and blessings be upon him) fixed half the blood money for them on account of their prayer, and said: "I am free of every Muslim who stays with a polytheist."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 2252