He shall be for a Sanctuary (comp. Ezekiel 11:16, "Yet will I be to them as a little Sanctuary"). A sanctuary is "a refuge" (Psalms 90:1; Psalms 91:9), and something more. It is a holy refuge, a place which is a refuge because of its holiness.
Its material counterpart in the Mosaic system is, not "the city of refuge," but the altar (1 Kings 1:50; 1 Kings 2:28). Both the houses of Israel; i.e. "the two reigning houses of Samaria and Judaea," both of which were Israelite.
Both the "houses" would ultimately forsake Jehovah, and find in him a "Snare" and a "Rock of offense."