Exodus 37:3-5

Young's Literal Translation

³ and he casteth for it four rings of gold, on its four feet, even two rings on its one side, and two rings on its second side;

⁴ and he maketh staves of shittim wood, and overlayeth them with gold,

⁵ and he bringeth in the staves into the rings, by the sides of the ark, to bear the ark.