Exodus 36:29
coupled together from bottom to top and fitted into a single ring. He made both corners in this way.
Berean Standard Bible
And they were coupled beneath, and coupled together at the head thereof, to one ring: thus he did to both of them in both the corners.
They were double beneath, and in the same way they were all the way to its top to one ring. He did this to both of them in the two corners.