And the request of forgiveness of Abraham for his father was only because of a promise he had made to him. But when it became apparent to Abraham that his father was an enemy to Allah, he disassociated himself from him. Indeed was Abraham compassionate and patient.
وَمَا كَانَ اسْتِغْفَارُ إِبْرَاهِيمَ لِأَبِيهِ إِلَّا عَنْ مَوْعِدَةٍ وَعَدَهَا إِيَّاهُ فَلَمَّا تَبَيَّنَ لَهُ أَنَّهُ عَدُوٌّ لِلَّهِ تَبَرَّأَ مِنْهُ ۚ إِنَّ إِبْرَاهِيمَ لَأَوَّاهٌ حَلِيمٌ