Jamieson, Fausset and Brown on Exodus 26:15-30

15-30. thou shalt make boards ... rear up the tabernacle according to the fashion ... which was showed thee--The tabernacle, from its name as well as from its general appearance and arrangements, was a tent; but from the description given in these verses, the boards that formed its walls, the five (cross) bars that strengthened them, and the middle bar that "reached from end to end," and gave it solidity and compactness, it was evidently a more substantial fabric than a light and fragile tent, probably on account of the weight of its various coverings as well as for the protection of its precious furniture.