Description and usage
The frames that made up the wall of the Tabernacle, as well as the posts that surrounded its court, stood in recessed metal bases, or mortises, which provided them with stability. The bases for the Tabernacle frames were made of silver, while those for the outer court were made of bronze.
Translation
The fact that there were forty bases for each side wall of the Tabernacle (EXO 26:19; EXO 26:20; EXO 26:21) means that there was one base for each tenon, or “two bases under one frame for its two tenons” (RSV). The repeated phrase, “two bases under another frame for its two tenons” (RSV), simply means that there were to be “two bases under each frame to hold its two projections” (GNT).