Pretty sure that's hadith. Anyone know the quranic verse?
If only it were just hadith. I wish. Now, you can take the hadith, as some progressives and apologists do, and use it to explain the following away as only applying to particular situations, but this is the truth of it:
Qur'an (4:89) - "They wish that you should disbelieve as they disbelieve, and then you would be equal; therefore take not to yourselves friends of them, until they emigrate in the way of God; then, if they turn their backs, take them, and slay them wherever you find them; take not to yourselves any one of them as friend or helper."
Qur'an (9:11-12) - "But if they repent and establish worship and pay the poor-due, then are they your brethren in religion. We detail Our revelations for a people who have knowledge. And if they break their pledges after their treaty (hath been made with you) and assail your religion, then fight the heads of disbelief - Lo! they have no binding oaths - in order that they may desist."