Exodus 37:1-3

And Bezalel made the ark of acacia wood: two cubits and a half was the length of it, and a cubit and a half the breadth of it, and a cubit and a half the height of it. And he overlaid it with pure gold within and without, and made a crown of gold to it round about. And he cast for it four rings of gold, in the four feet thereof; even two rings on the one side of it, and two rings on the other side of it.