مَا كَانَ لِلنَّبِيِّ وَالَّذِينَ آمَنُوا أَن يَسْتَغْفِرُوا لِلْمُشْرِكِينَ وَلَوْ كَانُوا أُولِي قُرْبَىٰ
“It's not befitting for the prophet and the believers to seek forgiveness for pagans even if they are close relatives”
Revealed after the Prophet ﷺ continued seeking forgiveness for Abu Talib without permission.