Exodus 26:1, 9, 12

“Moreover you shall make the tabernacle with ten curtains of fine twisted linen and blue and purple and scarlet material; you shall make them with cherubim, the work of a skillful workman.

You shall join five curtains by themselves and the other six curtains by themselves, and you shall double over the sixth curtain at the front of the tent.

The overlapping part that is left over in the curtains of the tent, the half curtain that is left over, shall lap over the back of the tabernacle.