Tafsir of At-Tawbah 9:115

"And Allah would not let a people go astray after He has guided them until He makes clear to them what they should avoid."

It means: Allah does not command the avoidance or abstention from something—such as seeking forgiveness for polytheists or other prohibited acts—and then hold His servants, whom He has guided to Islam, accountable for it, nor does He label them as "astray," nor does He abandon them, unless they proceed to commit it after the danger of it has been made clear to them and they know it is something that must be avoided and shunned.

As for before knowledge and clarification, there is no path [of blame] against them, just as they were not held accountable for drinking wine or trading one measure for two before the prohibition was revealed. This is an explanation of the excuse for those who feared accountability for seeking forgiveness for the polytheists before the prohibition regarding it was revealed.

In this verse, there is a severe warning that should not be overlooked: that a person guided to Islam, if they proceed to commit some of Allah’s prohibitions, falls under the ruling of being led astray.

The intended meaning of "what they should avoid" is that which is obligatory to avoid due to a prohibition. As for that which is known through reason—such as truthfulness in speech or returning a trust—it is not dependent upon [divine] revelation.

"Allah has already forgiven the Prophet and the Muhajirun (emigrants) and the Ansar (helpers) who followed him in the hour of difficulty after the hearts of a party of them had almost inclined [to doubt], then He forgave them. Indeed, He is to them Kind and Merciful."