3:90
إِنَّ ٱلَّذِينَ كَفَرُوا۟ بَعْدَ إِيمَـٰنِهِمْ ثُمَّ ٱزْدَادُوا۟ كُفْرًا لَّن تُقْبَلَ تَوْبَتُهُمْ وَأُو۟لَـٰٓئِكَ هُمُ ٱلضَّآلُّونَ
inna alladhīna kafarū baʿda īmānihim thumma iz'dādū kuf'ran lan tuq'bala tawbatuhum wa-ulāika humu l-ḍālūna
[although] the repentance of those who, having believed, then increase in their disbelief, will not be accepted. They are the ones who have gone [far] astray:
Verily, those who disbelieved after their Belief and then went on increasing in their disbelief (i.e. disbelief in the Qur’ân and in Prophet Muhammad صلى الله عليه وسلم) - never will their repentance be accepted [because they repent only by their tongues and not from their hearts]. And they are those who are astray.