Exalt ye the Lord our God (comp. Psalms 99:9; and see also Psalms 118:20 and Isaiah 25:1). And worship at his footstool. The "footstool of God" is everywhere (except in Isaiah 66:1) the ark of the covenant, which he that sat upon the cherubim touched, as it were, with his feet (see 1 Chronicles 28:2; Psalms 132:7; Lamentations 2:1; Isaiah 60:13).
Israel is called upon to worship God as he sits in his holy temple, enthroned above the cherubim, with his feet upon the mercy seat. For he is holy; rather, as in Psalms 99:3, holy is he.