Since we have said that the structure of the human body is symbolically indicated by the ark, we must take notice, also, that on the outside this body is enclosed by a hard and dense skin, to be a covering to all its parts; for nature has made this as a sort of coat, to prevent either cold or heat from being able to do man injury. The literal meaning of the expression is plain enough, for the door of the ark is carefully shut by divine virtue for the sake of security, lest the water should enter in at any part, as it was to be tossed about by the waves for an entire year.