470. And he set his right foot upon the sea, and his left upon the earth, signifies that the Lord has the whole church, as well those therein who are in its externals, as those who are in its internals, under His auspices and dominion. By "the sea and the earth" is signified the entire church; by "the sea," the external church, that is, they who are in its externals; and by "the earth," the internal church, that is, they who are in its internals (n. 398). By "setting his feet upon them," is signified to hold all in subjection to Himself, consequently, under His Divine auspices and dominion. Since the Lord's church on earth is beneath the heavens, therefore it is called "the footstool of His feet," as in these passages:
He hath cast forth out of heaven unto the earth the ornament of Israel, He doth not remember the footstool of His feet (Lam. 2:1). The earth is the footstool of My feet (Isa. 66:1). We will enter into His habitations, we will bow ourselves down at the footstool of His feet (Ps. 132:7). Thou shalt not swear by heaven, because it is the throne of God, neither by the earth, because it is the footstool of His feet (Matt. 5:34-35). I will make the place of My feet honorable (Isa. 60:13). Thou hast made Him to rule over the works of Thy hands, Thou hast put all things under His feet (Ps. 8:6). This is said of the Lord. That "he put his right foot upon the sea and his left upon the earth" is because they who are in the externals of the church have not so confirmed falsities with themselves as those who are in its internals.