Exodus 25:10

And they shall make an ark of shittim wood
A chest or coffer to put things into, and into this were to be put the two tables of stone on which the law was written, and it was to be made of the wood before mentioned, ( Exodus 25:5 ) this was a very eminent type of Christ, with whom the name of an ark, chest, or coffer where treasure lies, agrees; for the treasures of wisdom and knowledge, and the riches of grace, even all the fulness of it, lie in him; and all the epithets of this ark are suitable to him, as when it is called the ark of God, the ark of his strength, the glory of God, the face of God, Jehovah, and God himself, the holy ark, and ark of the covenant: and its being made of "shittim wood", which is an incorruptible wood, a wood that rots not, by which the Septuagint version here, and in ( Exodus 25:5 ) and elsewhere render it, may denote the duration of Christ in his person, and the natures united in it; in his divine nature, from everlasting to everlasting, he is God; in his human nature he saw no corruption, and though he died he lived again, and lives for evermore; in his offices, as Mediator, Redeemer, Saviour, prophet, priest, and King, he abideth for ever; and in his grace and the fulness of it, which, like himself, is the same today, yesterday, and forever:

two cubits and a half shall be the length thereof, and a cubit and a
half the breadth thereof, and a cubit and a half the height thereof;
if this cubit was a common cubit, consisting of a foot and a half or eighteen inches, then the length of this ark was forty five inches, and its breadth and height twenty seven each; according to Dr. Cumberland {k}, the Egyptian and Jewish cubit was above twenty one inches, and then the ark must be fifty three inches long or more, and thirty two and three quarters broad and high, or more: and Josephus ^F12 says, the length of it was five spans, and the breadth and height of it three spans each.