Qur'an 60:1

يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ لَا تَتَّخِذُوا۟ عَدُوِّى وَعَدُوَّكُمْ أَوْلِيَآءَ تُلْقُونَ إِلَيْهِم بِٱلْمَوَدَّةِ وَقَدْ كَفَرُوا۟ بِمَا جَآءَكُم مِّنَ ٱلْحَقِّ يُخْرِجُونَ ٱلرَّسُولَ وَإِيَّاكُمْ ۙ أَن تُؤْمِنُوا۟ بِٱللَّهِ رَبِّكُمْ إِن كُنتُمْ خَرَجْتُمْ جِهَـٰدًا فِى سَبِيلِى وَٱبْتِغَآءَ مَرْضَاتِى ۚ تُسِرُّونَ إِلَيْهِم بِٱلْمَوَدَّةِ وَأَنَا۠ أَعْلَمُ بِمَآ أَخْفَيْتُمْ وَمَآ أَعْلَنتُمْ ۚ وَمَن يَفْعَلْهُ مِنكُمْ فَقَدْ ضَلَّ سَوَآءَ ٱلسَّبِيلِ

“O you who have believed, do not take My enemies and your enemies as allies, extending to them affection while they have disbelieved in what came to you of the truth, having driven out the Prophet and yourselves [only] because you believe in Allāh, your Lord. If you have come out for jihād [i.e., fighting or striving] in My cause and seeking means to My approval, [take them not as friends]. You confide to them affection [i.e., instruction], but I am most knowing of what you have concealed and what you have declared. And whoever does it among you has certainly strayed from the soundness of the way.”

Al-Mumtahana 60:1 · Saheeh International