Exodus 36:12 in the King James Version
Fifty loops made he in one curtain, and fifty loops made he in the edge of the curtain which was in the coupling of the second: the loops held one curtain to another.
Context
11 He made loops of blue on the edge of the one curtain from the edge in the coupling. Likewise he made in the edge of the curtain that was outermost in the second coupling.
12 He made fifty loops in the one curtain, and he made fifty loops in the edge of the curtain that was in the second coupling. The loops were opposite to one another.
13 He made fifty clasps of gold, and coupled the curtains to one another with the clasps: so the tabernacle was a unit.