"Those who said to their brothers" means: of those believers who were killed on the day of Uhud, they were their brothers in terms of the faith that the hypocrites manifested. "And stayed behind" from the fighting, "If they had obeyed us, they would not have been killed," meaning: had they not gone out with Muhammad. Allah said to His Prophet: "Say: Then avert death from yourselves, if you are truthful," meaning: you are not able to avert it, which is to say: repel it. [Verses 169-171]