| Gill's Exposition of the Entire Bible 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 middle, particularly taken notice of, Exodus 26:28, how long these bars were it is not said, but it is reasonable to conclude that they reached the length of the tabernacle, which was thirty cubits; and as it was not easy to get bars of such a length, the notion of Josephus (u) perhaps, may be right, that each two consisted of divers parts which joined one another, the head of one entering into the hollow of the other and as he supposes they were five cubits long, a row of them must have six parts, which went along the sides, north and south, and the west end two, which was but ten cubits. (u) Ut supra. (Antiqu. l. 3. c. 6. sect. 3.)
Geneva Study BibleAnd thou shalt make bars of shittim wood; five for the boards of the one side of the tabernacle,
Scofield Reference NotesMargin shittim i.e. acacia.
Matthew Henry's Concise Commentary26:15-30 The sockets of silver each weighed about 115 pounds; they were placed in rows on the ground. In every pair of these sockets, a strong board of shittim-wood, covered with plates of gold, was fitted by mortises and tenons. Thus walls were formed for the two sides, and for the west end. The wall was further held together by bars, which passed through rings of gold. Over this the curtains were spread. Though movable, it was strong and firm. The materials were very costly. In all this it was a type of the church of God, built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief Corner-stone, Eph 2:20,21. | 
