Saeed bin Jubair (may Allah have mercy on him) narrates: A man came to Sayyiduna Ibn Abbas (may Allah be pleased with them both) and said: My father has died in the state of being a Christian. So he (Ibn Abbas) said: Give him a bath, shroud him, apply fragrance to him, then bury him. Then Sayyiduna Ibn Abbas (may Allah be pleased with them both) recited this verse:
﴿It is not for the Prophet and those who believe to ask forgiveness for the polytheists, even if they are close relatives, after it has become clear to them that they are companions of the Fire. * And the request of forgiveness by Abraham for his father was only because of a promise he had made to him. But when it became clear to him that he was an enemy to Allah, he dissociated himself from him.﴾
That is, it is not permissible for the Prophet and the believers to seek forgiveness for the polytheists, even if they are close relatives, after it has become clear to them that they are inhabitants of Hell. And Abraham’s seeking forgiveness for his father was only due to a promise he had made to him. Then when it became clear to him that he was an enemy to Allah the Exalted, Abraham (peace be upon him) dissociated himself from him. Then he said: When he died upon disbelief, it became clear to Abraham (peace be upon him) that he was an enemy to Allah the Exalted, so Abraham (peace be upon him) declared disassociation from him.