Exodus 26:4
"And thou shalt make loops of blue upon the edge of the one curtain from the selvedge in the coupling; and likewise shalt thou make in the uttermost edge of another curtain, in the coupling of the second."
Cross References (ranked by relevance)
Exodus 26:5
Fifty loops shalt thou make in the one curtain, and fifty loops shalt thou make in the edge of the curtain that is in the coupling of the second; that the loops may take hold one of another.
Exodus 36:17
And he made fifty loops upon the uttermost edge of the curtain in the coupling, and fifty loops made he upon the edge of the curtain which coupleth the second.