Quran 2:191 — The Heifer (Al-Baqarah)

وَاقتُلوهُم حَيثُ ثَقِفتُموهُم وَأَخرِجوهُم مِن حَيثُ أَخرَجوكُم ۚ وَالفِتنَةُ أَشَدُّ مِنَ القَتلِ ۚ وَلا تُقٰتِلوهُم عِندَ المَسجِدِ الحَرامِ حَتّىٰ يُقٰتِلوكُم فيهِ ۖ فَإِن قٰتَلوكُم فَاقتُلوهُم ۗ كَذٰلِكَ جَزاءُ الكٰفِرينَ

You may kill those who wage war against you, and you may evict them whence they evicted you. Oppression is worse than murder. Do not fight them at the Sacred Masjid, unless they attack you therein. If they attack you, you may kill them. This is the just retribution for those disbelievers.

[2:190] You may fight in the cause of GOD against those who attack you, but do not aggress. GOD does not love the aggressors.

[2:192] If they refrain, then GOD is Forgiver, Most Merciful.