Exodus 26:4

26:4 You are to make loops of blue material along the edge of the end curtain in one set, and in the same way you are to make loops in the outer edge of the end curtain in the second set.

Exodus 26:10

26:10 You are to make fifty loops along the edge of the end curtain in one set and fifty loops along the edge of the curtain that joins the second set.