they shall be separate beneath, but joined at the top, at the first ring. Thus shall it be with both of them; they shall form the two corners.
Very particular directions are here given about the boards of the tabernacle, which were to bear up the curtains, as the stakes of a tent which had need to be strong, Isa 54:2. These boards had tenons which fell into the mortises that were made for them in silver bases. God took care to have every thing strong, as well as fine, in his tabernacle.
Commenting on Exodus 26:15-30
And thou shalt make bars of shittim wood, Which being put into rings or staples of gold, kept the boards tight, close, and firm together: five for the boards of the one side of the tabernacle: for instance, the south side; four of these were placed, two at the upper end of the boards, and two at the lower end, and the fifth in the...
And they shall be coupled together beneath, and they shall be coupled together above the head of it unto one ring: thus shall it be for them both; they shall be for the two corners. (i) The Hebrew word signifies twins declaring that they should be as perfect and well joined as possible.