Genesis 6:16

In a cubit. This is understood by some, of the height of the window; by others, of the roof, which would be almost flat, like the top of a coach. Menoch supposes, that the whole ark was to be measured with the cubit in every part, from the bottom to the top; and the words of it, properly refer to the ark. --- Side, or at the end, about the middle way, that the animals might be coveyed easily to their stalls. The door would open into the story allotted to the beasts, and all things might enter it by a sort of bridge, or by sloping planks. (Calmet) --- Ordure might be thrown down into the lowest part of the ark, separated from the reservoir of fresh water, or might be brought up with ropes and buckets to the window at the top, which would easily open. (Tirinus)