Tafsir of Al-Jinn 72:13

{When we heard the guidance} It is their hearing of the Qur’an and their belief in it.

{He shall not fear} Meaning: He is not in a state of fear. The fa (ف) is included because the speech is structured as an implied subject (mubtada’) and predicate (khabar). Were it not for that, it would have been said: la yakhaf (لا يخف - jussive).

If you ask: What is the benefit of raising the verb and implying a subject before it so that it becomes a predicate, necessitating the inclusion of the fa, when all of that could have been avoided by simply saying la yakhaf?

I say: The benefit is that by doing so, it is as if one said: "He is one who does not fear." This indicates the certainty that the believer is inevitably saved and that he is the one specifically characterized by this, to the exclusion of others.

Al-A‘mash recited: fala yakhaf (فلا يخف), in the prohibitive sense.

{Neither loss nor injustice} Meaning: Neither the recompense of a loss (bakshan) nor an injustice (rahaqan). Because he did not deprive anyone of a right, nor did he commit an injustice against anyone, he does not fear their recompense.

In this is evidence that it is the duty of one who believes in Allah to avoid injustices. From this is the saying of the Prophet (peace and blessings be upon him): "The believer is the one whom people trust with their lives and their wealth."

It is also permissible that it means: He does not fear that he will be deprived of his reward, but rather he will be given the fullest recompense; nor does he fear that humiliation will overwhelm him (tarhaquhu), from the saying of the Almighty: {And humiliation will cover them} (10:27).

{And among us are Muslims, and among us are the unjust. So whoever has become Muslim, those have sought out the right path. But as for the unjust, they will be firewood for Hell.}