4:100
۞ وَمَن يُهَاجِرْ فِى سَبِيلِ ٱللَّهِ يَجِدْ فِى ٱلْأَرْضِ مُرَٰغَمًۭا كَثِيرًۭا وَسَعَةًۭ ۚ وَمَن يَخْرُجْ مِنۢ بَيْتِهِۦ مُهَاجِرًا إِلَى ٱللَّهِ وَرَسُولِهِۦ ثُمَّ يُدْرِكْهُ ٱلْمَوْتُ فَقَدْ وَقَعَ أَجْرُهُۥ عَلَى ٱللَّهِ ۗ وَكَانَ ٱللَّهُ غَفُورًۭا رَّحِيمًۭا
And whoever emigrates for the cause of Allah will find on the earth many [alternative] locations and abundance. And whoever leaves his home as an emigrant to Allah and His Messenger and then death overtakes him - his reward has already become incumbent upon Allah. And Allah is ever Forgiving and Merciful.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
The Prohibition of Residing Among the Disbelievers While Able to Emigrate
Al-Bukhari recorded that Muhammad bin `Abdur-Rahman, Abu Al-Aswad, said, "The people of Al-Madinah were forced to prepare an army (to fight against the people of Ash-Sham during the Khilafah of Abdullah bin Az-Zubayir at Makkah), and I was enlisted in it. Then I met `Ikrimah, the freed slave of Ibn `Abbas, and informed him (about it), and he forbade me strongly from doing so (i.e., to enlist in that army), and then he said to me, `Ibn `Abbas told me that some Muslims used to go out with the idolators increasing the size of their army against the Messenger of Allah ﷺ . Then, an arrow would hit one of them and kill him, or he would be struck on his neck (with a sword) and killed, and Allah sent down the Ayah,
إِنَّ الَّذِينَ تَوَفَّـهُمُ الْمَلَـئِكَةُ ظَـلِمِى أَنفُسِهِمْ
(Verily, as for those whom the angels take (in death) while they are wronging themselves)." Ad-Dahhak stated that this Ayah was revealed about some hypocrites who did not join the Messenger of Allah ﷺ but remained in Makkah and went out with the idolators for the battle of Badr. They were killed among those who were killed. Thus, this honorable Ayah was revealed about those who reside among the idolators, while able to perform Hijrah and unable to practice the faith. Such people will be committing injustice against themselves and falling into a prohibition according to the consensus and also according to this Ayah,
إِنَّ الَّذِينَ تَوَفَّـهُمُ الْمَلَـئِكَةُ ظَـلِمِى أَنفُسِهِمْ
(Verily, as for those whom the angels take (in death) while they are wronging themselves,) by refraining from Hijrah,