I have an urgent question regarding the Prophet's (Sallallahu Alaihi wa Sallam) parents. Were his parents idol worshippers? Were his parents Muslims? Will they enter Paradise? Will they be accountable on the Day of Judgment? Did the Prophet (Sallallahu Alaihi wa Sallam) ask forgiveness to Allah for his parents after their death?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

It is reported in a sound Hadeeth (narration) that the parents of the Prophet are in Hell. Muslim reported from Anas ibn Maalik that a man came to the Prophet and said, "O Messenger of Allaah, where is my father? The Prophet said: 'In Hell.' When the man turned back, the Prophet called him and said: 'Both my father and yours are in Hell.'"  [Muslim]

Abu Hurayrah said, "The Prophet visited the grave of his mother and wept and all those who were around him wept as well. Then he said: 'I sought the permission of my Lord to visit my mother's grave and He permitted me to do so. And I sought His permission to ask forgiveness for her and He did not permit me. (Now), visit the graves, they remind of death.'"

Thus, it is clear from the last Hadeeth that the Prophet was ordered not to seek forgiveness for his parents. It is also clear from the Quran that prohibiting asking for the forgiveness of the parents is because of their Shirk (disbelief). Allaah The Almighty Says (what means): {It is not (proper) for the Prophet and those who believe to ask Allaah's Forgiveness for the Mushrikoon (polytheists, idolaters, pagans, disbelievers in the Oneness of Allaah) even though they be of kin, after it has become clear to them that they are the dwellers of the Fire (because they died in a state of disbelief).} [Quran 9:113]. So, if it is certain that they were polytheists then that means they worshipped other than Allaah The Almighty.

Allaah Knows best.