Exodus 26:4

You shall make loops of blue on the edge of the one curtain from the edge in the coupling, and you shall do likewise on the edge of the curtain that is outermost in the second coupling.

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.