And had We appointed him, [Muḥammad] the Messenger, an angel, We would assuredly have made him a man, that is to say, We would have given him corporeal form, because an angel is light which is imperceptible to vision; they are a folk [aware only] of externals and are unable to perceive anything except what is sensory. But every sensory thing is either a body or a corporeal form. There is no form that corresponds to an angel who utters the truth such that he might be able to assume it physically, except for the human form, either because he should be a rational-speaking soul which would require such a form, or because of the necessary existence of genus-correspondence without which they would not be able to hear or receive speech from him.