Surah At-Tawbah 9:5

فَإِذَا ٱنسَلَخَ ٱلْأَشْهُرُ ٱلْحُرُمُ فَٱقْتُلُوا۟ ٱلْمُشْرِكِينَ حَيْثُ وَجَدتُّمُوهُمْ وَخُذُوهُمْ وَٱحْصُرُوهُمْ وَٱقْعُدُوا۟ لَهُمْ كُلَّ مَرْصَدٍ ۚ فَإِن تَابُوا۟ وَأَقَامُوا۟ ٱلصَّلَوٰةَ وَءَاتَوُا۟ ٱلزَّكَوٰةَ فَخَلُّوا۟ سَبِيلَهُمْ ۚ إِنَّ ٱللَّهَ غَفُورٌ رَّحِيمٌ

And when the inviolable months have passed, then kill the polytheists wherever you find them and capture them and besiege them and sit in wait for them at every place of ambush. But if they should repent, establish prayer, and give zakāh, let them [go] on their way. Indeed, Allāh is Forgiving and Merciful.

Translation: Saheeh International

Tafsir

Then when the sacred months have passed — that is at the end of the period of deferment — slay the idolaters wherever you find them be it during a lawful period or a sacred one and take them captive and confine them to castles and forts until they have no choice except being put to death or acceptance of Islam; …

Excerpt from Tafsir al-Jalalayn, commentary on 9:5, via Quran.com. The reader has the full commentary and 9 more tafsirs.