Surah At-Tawbah, Verse 123

يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُواْ قَٰتِلُواْ ٱلَّذِينَ يَلُونَكُم مِّنَ ٱلۡكُفَّارِ وَلۡيَجِدُواْ فِيكُمۡ غِلۡظَةٗۚ وَٱعۡلَمُوٓاْ أَنَّ ٱللَّهَ مَعَ ٱلۡمُتَّقِينَ١٢٣

yāayyuhā alladhīna āmanū qātilū alladhīna yalūnakum mina l-kufāri walyajidū fīkum ghil'ẓatan wa-iʿ'lamū anna l-laha maʿa l-mutaqīna

O you who have believed, fight against those adjacent to you of the disbelievers and let them find in you harshness. And know that Allāh is with the righteous.