To obtain boards of the required breadth, to or three planks were no doubt joined together according to the size of the trees.
Verse 17
Every board was to have two ידות (lit., hands or holders) to hold them upright, pegs therefore; and they were to be “bound to one another” (משׁלּב, from שׁלב in Chald. to connect, hence שׁלבּים in 1Ki 7:28, the corner plates that hold together the four sides of a chest), not “pegged into one another,” but joined together by a fastening dovetailed into the pegs, by which the latter were fastened still more firmly to the boards, and therefore had greater holding power than if each one had been simply sunk into the edge of the board.
verses 18-21
Twenty of these boards were to be prepared for the side of the dwelling that was turned towards the south, and forty sockets (אדנים foundations, Job 38:6) or bases for the pegs, i.e., to put the pegs of the boards into, that the boards might stand upright; and the same number of boards and sockets for the north side. תּימנה, “southward,” is added to נגבּה לפאת in Exo 26:18, to give a clearer definition of negeb, which primarily means the dry, and then the country to the south; an evident proof that at that time negeb was not established as a geographical term for the south, and therefore that it was not written here by a Palestinian, as Knobel supposes, but by Moses in the desert.
The form of the “sockets” is not explained, and even in Exo 38:27, in the summing up of the gifts presented for the work, it is merely stated that a talent of silver (about 93 lb.) was applied to every socket.
verses 22-24
Six boards were to be made for the back of the dwelling westwards (ימּה), and two boards “for the corners or angels of the dwelling at the two outermost (hinder) sides.” למקצּעת (for cornered), from מקצּע, equivalent to מקצוע an angle (Exo 26:24; Eze 46:21-22), from קצע to cut off, lit., a section, something cut off, hence an angle, or corner-piece. These corner boards (Exo 26:24) were to be “doubled (תּאמם) from below, and whole (תּמּים, integri, forming a whole) at its head (or towards its head, cf. אל Exo 36:29)
