Komentarz do Diwrej ha-jamim II 3:14

And he made the dividing curtain of blue, purple and he hung it on the door that was in the cubit between the two partitions, through which they would enter the Holy of Holies. Although it had doors, he hung it upon it as further (4:22): “And the entrance to the House, its inner doors to the Holy of Holies, etc.”

and he wrought cherubim into it pictures of cherubim.