[78] On which account Moses is directed also to take Aaron with him as an addition, Aaron being the symbol of uttered speech, "Behold," says God, "is not Aaron thy brother?" [81] For one rational nature being the mother of them both, it follows of course that the offspring are brothers, "I know that he will speak." For it is the office of the mind to comprehend, and of utterance to speak. "He," says God, "will speak for thee." For the mind not being able to give an adequate exposition of the part which is assigned to it, uses its neighbour speech as an interpreter, for the purpose of explaining what it feels.