Musnad Ahmad 33:558

Hassan narrated to us, Ibn Lahi'ah narrated to us, Abu al-Zubayr narrated to us, he said: I asked Jabir about the affair of Thaqif when they pledged allegiance? He said: "They stipulated to the Messenger of Allah, may Allah bless him and grant him peace, that there would be no charity (Zakat) upon them, and no Jihad."