The people of Medina were forced to prepare an army (to fight against the people of Sham during the caliphate of ʿAbdullah bin Az-Zubair at Mecca), and I was enlisted in it; Then I met ʿIkrima, the freed slave of Ibn ʿAbbas, and informed him (about it), and he forbade me strongly to do so (i.e. to enlist in that army), and then said, "Ibn ʿAbbas informed me that some Muslim people were with the pagans, increasing the number of the pagans against Messenger of Allah ﷺ. An arrow used to be shot which would hit one of them (the Muslims in the company of the pagans) and kill him, or he would be struck and killed (with a sword)." Then Allah revealed:-- "Verily! as for those whom the angels take (in death) while they are wronging themselves (by staying among the disbelievers)" (4.97) Abu AlAswad also narrated it.
أَنَّ نَاسًا مِنَ الْمُسْلِمِينَ كَانُوا مَعَ الْمُشْرِكِينَ يُكَثِّرُونَ سَوَادَ الْمُشْرِكِينَ عَلَى رَسُولِ اللَّهِ ﷺ يَأْتِي السَّهْمُ فَيُرْمَى بِهِ فَيُصِيبُ أَحَدَهُمْ فَيَقْتُلُهُ أَوْ يُضْرَبُ فَيُقْتَلُ فَأَنْزَلَ اللَّهُ {إِنَّ الَّذِينَ تَوَفَّاهُمُ الْمَلاَئِكَةُ ظَالِمِي أَنْفُسِهِمْ} الآيَةَ رَوَاهُ اللَّيْثُ عَنْ أَبِي الأَسْوَدِ