Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[115] As to the tabernacle itself, Moses placed it in the middle of that court, with its front to the east, that, when the sun arose, it might send its first rays upon it. Its length, when it was set up, was thirty cubits, and its breadth was twelve [ten] cubits. The one of its walls was on the south, and the other was exposed to the north, and on the back part of it remained the west. It was necessary that its height should be equal to its breadth [ten cubits]. There were also pillars made of wood, twenty on each side; they were wrought into a quadrangular figure, in breadth a cubit and a half, but the thickness was four fingers: they had thin plates of gold affixed to them on both sides, inwardly and outwardly: they had each of them two tenons belonging to them, inserted into their bases, and these were of silver, in each of which bases there was a socket to receive the tenon; but the pillars on the west wall were six. Now all these tenons and sockets accurately fitted one another, insomuch that the joints were invisible, and both seemed to be one entire and united wall. It was also covered with gold, both within and without. The number of pillars was equal on the opposite sides, and there were on each part twenty, and every one of them had the third part of a span in thickness; so that the number of thirty cubits were fully made up between them; but as to the wall behind, where the six pillars made up together only nine cubits, they made two other pillars, and cut them out of one cubit, which they placed in the corners, and made them equally fine with the other. Now every one of the pillars had rings of gold affixed to their fronts outward, as if they had taken root in the pillars, and stood one row over against another round about, through which were inserted bars gilt over with gold, each of them five cubits long, and these bound together the pillars, the head of one bar running into another, after the nature of one tenon inserted into another; but for the wall behind, there was but one row of bars that went through all the pillars, into which row ran the ends of the bars on each side of the longer walls; the male with its female being so fastened in their joints, that they held the whole firmly together; and for this reason was all this joined so fast together, that the tabernacle might not be shaken, either by the winds, or by any other means, but that it might preserve itself quiet and immovable continually.