It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "I have been commanded to fight the people until they say La ilaha illa Allah (there is no god but Allah). When they say it, they have safeguarded their lives and their wealth from me, except by its right, and their reckoning is with Allah, the Mighty and Majestic."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1733