Musannaf Ibn Abi Shayba 28:581

Al-Fadl ibn Dukayn narrated to us, he said: Aban ibn Abdullah narrated to us, he said: Ibrahim ibn Jarir narrated to me, from Jarir, who said: The Prophet of Allah, may Allah bless him and grant him peace, sent me to Yemen to fight them and call them [to Islam]. If they said, "There is no god but Allah," their wealth and their blood became forbidden to you.