Exodus 26:26

בריחים are BOLTS, as the Targum translates it: עברין; in old French esparres. חמשה לקרשי צלע המשכן FIVE FOR THE BOARDS OF THE ONE SIDE OF THE TABERNACLE — The five were really only three, but the upper and the lower bolts were each composed of two pieces, the one reaching to the middle of the wall from one side and the other reaching to the middle of the wall from the other side, the one passing through the outermost ring from one side and the other passing through the outermost ring from the other side, until, passing through all the intermediate rings, they met one against each other. Thus the upper and lower bolts were two which were made up of four. As to the middle bolt its length was equal to that of the entire wall passing from one end of the wall to the other end, for it is said, “And the middle bolt etc. shall reach from extremity to extremity.” This was therefore in one piece, and so we have the five of which this passage speaks. For the upper and lower bolts had rings on the boards into which were to be inserted two rings for each board. The bolts were משלשים i. e. placed at three equidistant points along the ten cubits that formed the height of the board, thus dividing the height into four equal portions, — one portion extending from the upper ring to the top of the board, another from the lower ring to the bottom, each portion being a quarter of the board’s height, and the other two portions were between the rings (from one ring to the central bolt and from there to the other ring). This was done in order that all the rings in one row should be exactly opposite one another so that the bolt could be easily inserted. The middle bolt, however, had no rings, but the) wards were grooved right through their thickness and it (the middle bolt) passed through them by way of these grooves which were exactly opposite one another (all in one straight line). This is the meaning of what is stated, “[and the middle bolt] in the midst of the boards.” The upper two and the lower two bolts on the north and south side were each 15 cubits long, whilst the middle bolt was 30 cubits long. That is what Scripture means by saying of this bolt that it shall reach “from extremity to extremity” — from east to west. Of the five bolts on the west side the length of the two upper and the two lower ones was each six cubits whilst the middle one hade its length twelve cubits corresponding to the aggregate width of the eight boards (each of which was one cubit and a half). This is how it is explained in the Boraitha treating of the construction of the Tabernacle.

וְעָשִׂ֥יתָ בְרִיחִ֖ם עֲצֵ֣י שִׁטִּ֑ים חֲמִשָּׁ֕ה לְקַרְשֵׁ֥י צֶֽלַע־הַמִּשְׁכָּ֖ן הָאֶחָֽד׃

And thou shalt make bars of shittim wood; five for the boards of the one side of the tabernacle,