Tafsir of Al-Hashr 59:13

"You are indeed more fearful" — meaning, you are more formidable, considering that 'fear' (rahbah) is used here as a verbal noun derived from a passive construction, because those addressed—the believers—are the ones feared, not the ones fearing.

"In their chests than Allah" — meaning, their fear of you in secret is more intense than the fear of Allah the Almighty which they manifest to you. They used to show them intense fear of Allah the Almighty. It is also permissible that the meaning is that they fear you in their chests more than they fear Allah the Almighty, due to the intensity of their might and bravery, although they would not manifest that. It has been said: the phrase "in their chests," according to the first interpretation, is for emphasis and vivid portrayal, similar to saying, "I saw it with my own eyes."

"That" — meaning, what was mentioned regarding you being more formidable in their chests than Allah the Almighty — "is because they are a people who do not understand" anything, so that they might know the greatness of Allah the Almighty and thus fear Him with the fear He, the Glorified and Exalted, deserves.

It is said that those intended by this are the Jews; it is also said they are the hypocrites, and it is said they are both groups.