and on the Day of Resurrection he will be grouped with Qarun, Pharaoh, Haman, and Ubayy ibn Khalaf.’ Narrated by Ibn Majah, Ahmad, al-Tabarani, and Ibn Hibban in his Sahih; its chain is hasan (fair).
Yet the disbelief involved here is not of the sort that Allah can never forgive or that would preclude entry into Paradise; such forgiveness is possible. The Prophet ﷺ said: ‘Five prayers Allah has prescribed for His servants. Whoever comes before Him having performed them all, without neglecting any of them out of disdain for their due, has a covenant with Allah that He will admit him to Paradise. Whoever fails to perform them has no covenant with Allah: if He wills, He will punish him, and if He wills, He will admit him to Paradise.’ Reported by Malik, Abū Dāwūd, al-Nasāʾī, Ibn Majah, and Ahmad with an authentic chain.
Be aware that many hadiths attribute disbelief to someone who commits a major sin; in some of them he is explicitly called a disbeliever. The Prophet ﷺ said, ‘Reviling a Muslim is immorality, and fighting him is disbelief.’ He also said, ‘No man who knowingly claims someone other than his father as his father does so except in disbelief.’ And: ‘Two traits found among the people are acts of disbelief: attacking lineage and wailing over the dead.’ And: ‘Do not turn back after me as disbelievers, striking one another’s necks.’ And: ‘Any slave who absconds from his masters has disbelieved until he returns to them.’ And: ‘Whoever says to his brother, “You disbeliever,” the charge returns to one of them; if it is true, then to the one described, otherwise it rebounds upon the speaker.’ All of these reports are found in the two Sahihs.
Once we understand that disbelief is of varying degrees, and that some forms do not doom a person to eternal Hellfire, there is no need for strained interpretation. Whomever the Messenger of Allah ﷺ called a disbeliever, we likewise call a disbeliever—and we go no further than that. For more on this, see al-Shawkani, 1/254–260.