Exodus 36:10-12

Young's Literal Translation

¹⁰ And he joineth the five curtains one unto another, and the [other] five curtains he hath joined one unto another;

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.