It means what Allah has commanded to be feared and avoided, such as seeking forgiveness for the polytheists and other things He has prohibited, and He has made it clear that it is forbidden. His servants whom He has guided to Islam are not held accountable for it, nor does He call them misguided, nor does He forsake them unless they engage in it after the prohibition has been made clear to them and they know that it is obligatory to fear and avoid it. As for before knowledge and clarification, there is no blame upon them, just as they are not held accountable for drinking alcohol or for selling a measure for two measures before the prohibition. This is a clarification of the excuse for those who fear accountability for seeking forgiveness for the polytheists before the prohibition was revealed. In this verse, there is something severe that should not be overlooked: that the one who is guided to Islam, if he engages in some of Allah's prohibitions, falls under the ruling of misguidance.

And what is meant by what they should fear: what must be avoided due to the prohibition. As for what is known by reason, [Mahamud said: 'As for what is understood to be prohibited by reason...'] Ahmad said: this is a derivation based on the principle of good and evil, and that reason is the judge, while the Sharia is the revealer of what is obscure to it, following its implications. This principle has been proven false in more than one instance, and Allah is the Grantor of success.

As for the statement 'as for what is known by reason, such as truthfulness,' it is based on the doctrine of the Mu'tazila that a ruling can be known by reason, while the people of Sunnah hold that there is no ruling before the Sharia. (A) In the report, and the return of the trust is not contingent upon the prohibition.