John Gill Bible Commentary

Notwithstanding, if the land of your possession be unclean,.... That is, if it was judged to be so by them, because not cleansed from the sins of the former inhabitants of it by sacrifice, or because there was no altar in it to offer up sacrifice for the expiation of sin: then pass ye over unto the land of the possession of the Lord, wherein the Lord's tabernacle dwelleth; if you repent of the choice you have made of a country to dwell in, quit it, and come over into the land of Canaan, which the Lord has taken possession of, and residence in, and where his tabernacle is fixed, the place of his presence and worship, and where an altar is erected to sacrifice upon: and take possession among us; they were willing to quit possession of their own, and make room for them in each of their tribes, and even though they straitened themselves, and parted with much of their estates, rather than they should make a schism, or go into idolatrous practices; which was a brave, noble, spirit indeed, and showed their great concern for the honour and glory of God, and his worship, and their love to their brethren, and affectionate regard for their spiritual welfare, above their own private, personal, and temporal good: but rebel not against the Lord: the Word of the Lord, as the Targum, either Christ the essential Word, the Angel of Jehovah's presence, or his word of command: nor rebel against us; by breaking off from us, and setting up another religion or form of worship: in building you an altar beside the altar of the Lord our God: which ought to be common to both, and no other to be set up against it, or used beside it.