Professor Everett Fox of Clark University noted that "glory" (, "kevod") and "stubbornness" (, "kaved lev") are leading words throughout the book of Exodus that give it a sense of unity. Similarly, Propp identified the root "kvd" — connoting heaviness, glory, wealth, and firmness — as a recurring theme in Exodus: Moses suffered from a heavy mouth in and heavy arms in Pharaoh had firmness of heart in 28; 34; and Pharaoh made Israel's labor heavy in God in response sent heavy plagues in 18, 24; and so that God might be glorified over Pharaoh in 17, and 18; and the book culminates with the descent of God's fiery Glory, described as a "heavy cloud," first upon Sinai and later upon the Tabernacle in 22; and