Musnad Ahmad 33:445

Abu Amir narrated to us, Zuhayr narrated to us, and Abu al-Nadr narrated to us, Sharik narrated to us, from Abdullah ibn Muhammad ibn Aqil, from Jabir, that the Prophet, peace and blessings of Allah be upon him, said: "I have been commanded to fight the people until they say: 'There is no god but Allah.' If they say it, they have protected their blood, their wealth, and their souls from me, except by its right, and their reckoning is with Allah."