Five is the number of responsibility (cf. note Matt. 25:21a), and two is the number of testimony (Deut. 19:15). The two sets of the five curtains joined to one another (vv. 4-6) signify the continuous life of the Lord Jesus as a life of responsibility for a testimony.
The joining of the two sets of five curtains resulted in a large sheet measuring forty cubits by twenty-eight cubits. Twenty-eight is composed of four times seven, the number four signifying man as God’s creature (Ezek. 1:5) and the number seven signifying completion (see note Rev. 1:41a). Thus, the length of each curtain also signifies the completeness and perfection of the Lord Jesus as a man (cf. note Exo. 26:11). The number forty signifies testing and trials (Heb. 3:9; Matt. 4:2). Hence, the forty cubits signify that the Lord’s completeness and perfection as a man have been tested, and He is approved by both God and man.
The tabernacle itself was thirty cubits in length and ten cubits in both width and height (see note Exo. 26:181 and note Exo. 26:331). When the tabernacle was erected, the sheet of linen curtains was spread upon the standing boards (vv. 15-30). The sheet hung over the rear of the tabernacle by ten cubits and over the sides by nine cubits each, with no overhang at the front, the entrance, of the tabernacle. The number nine, composed of three times three, signifies the Triune God in resurrection. The overhang of nine cubits on each side signifies that the Lord Jesus was a perfect and complete man overflowing with the Triune God in resurrection in an even and balanced way.