At Tawbah Ayah 113

مَا كَانَ لِلنَّبِىِّ وَٱلَّذِينَ ءَامَنُوٓاْ أَن يَسْتَغْفِرُواْ لِلْمُشْرِكِينَ وَلَوْ كَانُوٓاْ أُوْلِى قُرْبَىٰ مِنۢ بَعْدِ مَا تَبَيَّنَ لَهُمْ أَنَّهُمْ أَصْحَـٰبُ ٱلْجَحِيمِ ١١٣ It is not ?proper? for the Prophet and the believers to seek forgiveness for the polytheists, even if they were close relatives, after it has become clear to the believers that they are bound for the Hellfire.