Are the Prophet's parents—peace and blessings be upon him—among the dwellers of Hellfire, and is he permitted to intercede for them, and what is the evidence for that?

The fate of the Prophet's parents in the Hereafter is that they died in a state of disbelief, and the intercession for them to be saved from the Fire will not benefit them. The evidence for this is the Almighty's saying: "It is not for the Prophet and those who have believed to ask forgiveness for polytheists, even if they were relatives, after it has become clear to them that they are companions of Hellfire." The Prophet had sought permission from his Lord to ask forgiveness for his mother, but he was not granted it. However, intercession for them to have their torment lightened is permissible, as it has been established that Abu Talib is in a shallow pool of fire, and were it not for the Prophet's intercession, he would have been in the lowest depths.