The saying of Allah, exalted be His praise: "Then when the sacred months have passed, kill the polytheists wherever you find them." [Surah al-Tawbah: 5], (the full) two verses.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / Q17947
Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "I have been commanded to fight until they say 'La ilaha illallah' (There is no god but Allah). Whoever says the testimony has protected his wealth and his life from us, except for the rights of Islam, and his reckoning is with Allah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17947
Muharrar bin Abi Hurayrah (may Allah have mercy on him) narrates from his father, Sayyiduna Abu Hurayrah (may Allah be pleased with him), who said: When the Messenger of Allah (peace and blessings be upon him) sent Sayyiduna Ali (may Allah be pleased with him) to announce the declaration of disassociation (Bara'ah) to the polytheists, I was with him, and I kept proclaiming until my voice grew hoarse. I asked my father: Father, what were you proclaiming? He said: We were commanded to proclaim: "None will enter Paradise except a believer; whoever has a treaty with the Messenger of Allah (peace and blessings be upon him), its term is four months, and when the four months have passed, then Allah and His Messenger are free of the polytheists ("that Allah is free of the polytheists, and so is His Messenger" [Surah al-Tawbah: 3]); and no polytheist shall circumambulate the Ka'bah after this year," or he said: "No polytheist shall circumambulate after this day."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17948