Surah Al-Baqarah, ayah 217

يَسۡـَٔلُونَكَ عَنِ ٱلشَّهۡرِ ٱلۡحَرَامِ قِتَالٖ فِيهِۖ قُلۡ قِتَالٞ فِيهِ كَبِيرٞۚ وَصَدٌّ عَن سَبِيلِ ٱللَّهِ وَكُفۡرُۢ بِهِۦ وَٱلۡمَسۡجِدِ ٱلۡحَرَامِ وَإِخۡرَاجُ أَهۡلِهِۦ مِنۡهُ أَكۡبَرُ عِندَ ٱللَّهِۚ وَٱلۡفِتۡنَةُ أَكۡبَرُ مِنَ ٱلۡقَتۡلِۗ وَلَا يَزَالُونَ يُقَٰتِلُونَكُمۡ حَتَّىٰ يَرُدُّوكُمۡ عَن دِينِكُمۡ إِنِ ٱسۡتَطَٰعُواْۚ وَمَن يَرۡتَدِدۡ مِنكُمۡ عَن دِينِهِۦ فَيَمُتۡ وَهُوَ كَافِرٞ فَأُوْلَٰٓئِكَ حَبِطَتۡ أَعۡمَٰلُهُمۡ فِي ٱلدُّنۡيَا وَٱلۡأٓخِرَةِۖ وَأُوْلَٰٓئِكَ أَصۡحَٰبُ ٱلنَّارِۖ هُمۡ فِيهَا خَٰلِدُونَ ٢١٧

Yas'alūnaka 'anish-shahril-harāmi qitālin fīhi qul qitālun fīhi kabīrun wasaddun 'an sabīlillāhi wakufru bihī wal-masjidil-harāmi wa ikhrāju ahlihī minhu akbaru 'indallāhi wal-fitnatu akbaru minal-qatli walā yazālūna yuqātilūnakum hattā yaruddūkum 'an dīnikum inistatā'ū waman yartadid minkum 'an dīnihī fayamut wahuwa kāfirun fa ulā'ika habitat a'māluhum fid-dunyā wal-ākhirati wa ulā'ika ashābun-nāri hum fīhā khālidūn

They ask you about the sacred month⁷⁸ - about fighting therein. Say, "Fighting therein is great [sin], but averting [people] from the way of Allāh and disbelief in Him and [preventing access to] al-Masjid al-Ḥarām and the expulsion of its people therefrom are greater [evil] in the sight of Allāh. And fitnah⁷⁹ is greater than killing." And they will continue to fight you until they turn you back from your religion if they are able. And whoever of you reverts from his religion [to disbelief] and dies while he is a disbeliever - for those, their deeds have become worthless in this world and the Hereafter, and those are the companions of the Fire; they will abide therein eternally.