Clarke's Bible Commentary - Exodus 26:14
Verse 14. Rams' skins dyed red] See the note on "Exodus xxv. 5". This was the third covering; and what is called the badgers' skins was the fourth. See the note on "chap. xxv. 5". Why there should have been four coverings does not appear. They might have been designed partly for respect; and partly to keep off dust and dirt, and the extremely fine sand which in that desert rises as it were on every breeze; and partly to keep off the intense heat of the sun, which would otherwise have destroyed the poles, bars, boards, and the whole of the wood work. As to the conjecture of some that "the four coverings were intended the better to keep off the rain," it must appear unfounded to those who know that in that desert rain was rarely ever seen.
Matthew Henry Commentary
Verses 7-14 - The curtains of meaner materials, being made both longer and broader covered the others, and were defended by coverings of skins. The whol represents the person and doctrine of Christ, and the church of tru Christians, and all heavenly things, which outwardly are mean, but inwardly, and in the sight of God, are glorious and precious.
Original Hebrew
ועשׂית 6213 מכסה 4372 לאהל 168 ערת 5785 אילם 352 מאדמים 119 ומכסה 4372 ערת 5785 תחשׁים 8476 מלמעלה׃ 4605