They are (Those who, while they sat at home) and refrained from jihad, (said of their brethren) the hypocrites in Medina: (If they) i.e. Muhammad and his Companions by remaining in Medina (had been guided by us they would not have been slain) in their military expedition. (Say) O Muhammad, to the hypocrites: (Then avert death from yourselves if ye are truthful) in your claim.