In the last days; literally, in the sequel of the days; but generally used of a remote future (Genesis 49:1; Numbers 24:14; Deuteronomy 4:30, etc.). The mountain of the Lord's house; i.e. the Church, the true Zion, which is to be the antitype of the existing Zion, and is therefore given its material attributes.
Spiritually, it would be a "mountain," as "a city set on a hill," which "could not be hid" (Matthew 5:14); and again, as occupying a position from which it would command the whole earth. In the top of the mountains; rather, at the head of the mountains; i.
e. with pre-eminence over them. The metaphor is drawn from the common physical fact of a high mountain range culminating in a single supreme eminence. So Mount Hermon towers above the rest of the Antilibanus, Demavend over Elburz, Rowandiz over Zagros.
The "mountains" above which the true Zion shall tower are the kingdoms, or perhaps the religions, of the earth. All nations; literally, all the nations; i.e. "all the nations of the earth" (comp. Psalms 72:11).
Shall flow; or, stream. A constant accession of converts from all quarters is intended. These are represented as continually streaming upward into the holy mountain of God's house.