Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) said: "But those people who are the inhabitants of Hell (i.e., those who are to remain there forever, such as disbelievers and polytheists), they will not die in Hell, and among the people there will be some (disobedient ones) whose sins will cause the Fire to seize them, and they will burn in it until, when they are burnt and become like coal, then the command for their intercession will be given. Thus, they will come out of Hell in groups and will be spread out in the rivers of Paradise, and it will be said to the people of Paradise: 'Pour water over them.'” He said: “So the people of Paradise will pour water over those who have come from Hell, by which their flesh will grow just as a seed grows and flourishes in the flow of water (i.e., they will recover very quickly).”
(Imam Nawawi rahimahullah said: The meaning of this hadith is that those people who are disbelievers and are deserving of remaining in Hellfire forever, neither will they die nor will they live, and in no way will they be relieved from the punishment nor will they attain comfort, just as it is stated in the Noble Qur’an: For those who disbelieve, there is the fire of Hell; neither will a decree be made for them so that they die, nor will its punishment be lightened for them... [فاطر 36]. Likewise, the statement of Allah the Exalted is: «﴿ثُمَّلَايَمُوتُفِيهَاوَلَايَحْيَىٰ﴾ [الأعلى : 13]». The position of the people of truth (Ahl al-Haqq) is that both the comfort of Paradise and the punishment of Hell are everlasting and eternal. And those people who, due to their sins, will enter Hellfire are those who were believers but became involved in sins. Allah Ta’ala will burn them in the fire of Hell until they become like coal, then they will be taken out from Hell, as is clarified in the hadith.)