Qur'an 9:114

وَمَا كَانَ ٱسْتِغْفَارُ إِبْرَٰهِيمَ لِأَبِيهِ إِلَّا عَن مَّوْعِدَةٍ وَعَدَهَآ إِيَّاهُ فَلَمَّا تَبَيَّنَ لَهُۥٓ أَنَّهُۥ عَدُوٌّ لِّلَّهِ تَبَرَّأَ مِنْهُ ۚ إِنَّ إِبْرَٰهِيمَ لَأَوَّٰهٌ حَلِيمٌ

The prayer of Abraham for the forgiveness of his father was only because of a promise he had promised him, but when it had become clear unto him that he (his father) was an enemy to Allah he (Abraham) disowned him. Lo! Abraham was soft of heart, long-suffering.