At-Tawbah · 9:114

114. Abraham’s seeking forgiveness for his polytheist father was only because of a promise he had made to him to do so, in the hope that he would submit. When it became clear to Abraham that his father was an enemy of Allah, due to the advice not being of benefit to him or due to his coming to know through revelation that he will die as a disbeliever, he renounced him. He had asked forgiveness for him on the basis of his own reasoning and not in contradiction of any law that Allah had revealed to him. Abraham (peace be with him) used to frequently turn to Allah in humility and he used to overlook and pardon his people who were wrongdoers.