Exodus 36:9-13
English Standard Version
10He coupled five curtains to one another, and the other five curtains he coupled to one another.
11He made loops of blue on the edge of the outermost curtain of the first set. Likewise he made them on the edge of the outermost curtain of the second set.
12He made fifty loops on the one curtain, and he made fifty loops on the edge of the curtain that was in the second set. The loops were opposite one another.
13And he made fifty clasps of gold, and coupled the curtains one to the other with clasps. So the tabernacle was a single whole.