"We must consider the words, "the heavens were opened" (Ezek. i. 1); they give the key to the understanding of the whole. The figure of opening, also that of opening the gates, occurs frequently in the books of the prophets... When he commences to describe the firmament in detail, he says, "the firmament," without adding the words "the likeness of," for he says, "And I looked, and behold, in the firmament that was above the head of the cherubims there appeared over them as it were a sapphire stone, as the appearance of the likeness of a throne" (Ezek x. 1). Here the prophet speaks of "the firmament" and not of "the likeness of the firmament,"..."