Exodus 36:14-18

And he made curtains of goats' hair for the tent over the tabernacle: eleven curtains he made them. The length of one curtain was thirty cubits, and four cubits was the breadth of one curtain: the eleven curtains were of one size. And he coupled five curtains by themselves, and six curtains by themselves. 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. And he made fifty taches of brass to couple the tent together, that it might be one.