3:120
إِن تَمْسَسْكُمْ حَسَنَةٌۭ تَسُؤْهُمْ وَإِن تُصِبْكُمْ سَيِّئَةٌۭ يَفْرَحُوا۟ بِهَا ۖ وَإِن تَصْبِرُوا۟ وَتَتَّقُوا۟ لَا يَضُرُّكُمْ كَيْدُهُمْ شَيْـًٔا ۗ إِنَّ ٱللَّهَ بِمَا يَعْمَلُونَ مُحِيطٌۭ
If good touches you, it distresses them; but if harm strikes you, they rejoice at it. And if you are patient and fear Allah, their plot will not harm you at all. Indeed, Allah is encompassing of what they do.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
Prohibition of Taking Allies From Disbelievers Who Ridicule Islam
Allah forbids His believing servants from taking the hypocrites as allies, so that the hypocrites do not have the opportunity to expose the secrets of the believers and their plans against their enemies. The hypocrites try their very best to confuse, oppose and harm the believers any way they can, and by using any wicked, evil means at their disposal. They wish the very worst and difficult conditions for the believers. Allah said,
لاَ تَتَّخِذُواْ بِطَانَةً مِّن دُونِكُمْ
(Take not as (your) Bitanah those other than your own) 3:118, in reference to taking followers of other religions as consultants and allies, for advisors of a certain person have access to his most secret affairs. Al-Bukhari and An-Nasa'i recorded that, Abu Sa`id said that the Messenger of Allah ﷺ said,
«مَا بَعَثَ اللهُ مِنْ نَبِيَ وَلَا اسْتَخْلَفَ مِنْ خَلِيفَةٍ إِلَّا كَانَتْ لَهُ بِطَانَتَانِ: بِطَانَةٌ تَأْمُرُهُ بِالْخَيْرِ وَتَحُضُّهُ عَلَيْهِ، وَبِطَانَةٌ تَأْمُرُهُ بِالسُّوءِ وَتَحُضُّهُ عَلَيْهِ، وَالْمَعْصُومُ مَنْ عَصَمَ الله»
(Allah has not sent any Prophet nor was there any Khalifah but they have two types of allies, one that commands him with righteousness and advises it, and another that commands him with evil and advises him with it. Only those whom Allah gives immunity are immune.)