Is the difficult reckoning for the unbeliever and the hypocrite only, or does it include the transgressor as well?

The discussion of accountability is not limited to disbelievers and hypocrites, but also includes some disobedient monotheists whose evil deeds outweigh their good ones. The accountability of servants varies: some face a difficult reckoning, and these are the disbelievers and criminals, as well as some disobedient monotheists whose reckoning will be prolonged due to the multitude of their sins. Other servants will be held to an easy reckoning; these are those who are not subjected to a detailed discussion of their deeds, but rather their sins are presented to them and then overlooked.

The meaning of "nūqisha al-ḥisāb" (the reckoning was discussed in detail) is that it was thoroughly investigated. This leads to torment or destruction because shortcomings are prevalent among servants, and whoever is thoroughly investigated will perish, unless Allah pardons and forgives anything less than polytheism for whom He wills.

There will be three groups on the Day of Judgment: a group that will not be held accountable at all, a group that will be held to an easy reckoning, and both of these are from among the believers. The third group will be held to a severe reckoning, and this includes both Muslims and disbelievers.

The people of Paradise are of layers: the first will enter without reckoning, punishment, or presentation of deeds. The second will be held to an easy reckoning and will enter Paradise without any ill or punishment. The third will be subjected to a detailed discussion of their reckoning and then punished; these are monotheists who will inevitably be brought out of the Fire.