Exodus 36:11-13

Young's Literal Translation

¹¹ and he maketh loops of blue on the edge of the one curtain, at the end, in the joining; so he hath made in the edge of the outmost curtain, in the joining of the second;

¹² fifty loops he hath made in the one curtain, and fifty loops hath he made in the end of the curtain which [is] in the joining of the second; the loops are taking hold one on another.

¹³ And he maketh fifty hooks of gold, and joineth the curtains one unto another by the hooks, and the tabernacle is one.