abraham asked forgiveness for his father only because of a promise he had made to him. but when it became clear to him that he was an enemy of god he disowned him. abraham was kind and clement.
وما كان استغفار إبراهيم لأبيه إلا عن موعدة وعدها إياه فلما تبين له أنه عدو لله تبرأ منه إن إبراهيم لأواه حليم