2:256
لَآ إِكْرَاهَ فِى ٱلدِّينِ ۖ قَد تَّبَيَّنَ ٱلرُّشْدُ مِنَ ٱلْغَىِّ ۚ فَمَن يَكْفُرْ بِٱلطَّٰغُوتِ وَيُؤْمِنۢ بِٱللَّهِ فَقَدِ ٱسْتَمْسَكَ بِٱلْعُرْوَةِ ٱلْوُثْقَىٰ لَا ٱنفِصَامَ لَهَا ۗ وَٱللَّهُ سَمِيعٌ عَلِيمٌ
There shall be no compulsion in [acceptance of] the religion. The right course has become clear from the wrong. So whoever disbelieves in Taghut and believes in Allah has grasped the most trustworthy handhold with no break in it. And Allah is Hearing and Knowing.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
No Compulsion in Religion
Allah said,
لاَ إِكْرَاهَ فِى الدِّينِ
(There is no compulsion in religion), meaning, "Do not force anyone to become Muslim, for Islam is plain and clear, and its proofs and evidence are plain and clear. Therefore, there is no need to force anyone to embrace Islam. Rather, whoever Allah directs to Islam, opens his heart for it and enlightens his mind, will embrace Islam with certainty. Whoever Allah blinds his heart and seals his hearing and sight, then he will not benefit from being forced to embrace Islam."
It was reported that the Ansar were the reason behind revealing this Ayah, although its indication is general in meaning. Ibn Jarir recorded that Ibn `Abbas said that before Islam, "When (an Ansar) woman would not bear children who would live, she would vow that if she gives birth to a child who remains alive, she would raise him as a Jew. When Banu An-Nadir (the Jewish tribe) were evacuated from Al-Madinah, some of the children of the Ansar were being raised among them, and the Ansar said, `We will not abandon our children.' Allah revealed,
لاَ إِكْرَاهَ فِى الدِّينِ قَد تَّبَيَّنَ الرُّشْدُ مِنَ الْغَيِّ