For I will cleanse their blood that I have not cleansed: for the LORD dwelleth in Zion. For I will cleanse their blood - נקיתי nikkeythi, I will avenge the slaughter and martyrdom of my people, which I have not yet avenged.
Persecuting nations and persecuting Churches shall all come, sooner or later, under the stroke of vindictive justice.
For the Lord dwelleth in Zion - He shall be the life, soul, spirit, and defense of his Church for ever. This prophet, who has many things similar to Ezekiel, ends his prophecy nearly in the same way:
Ezekiel says of the glory of the Church, יהוה שמה Yehovah shammah, The Lord Is There.
Joel says, יהוה שכן בציון Yehovah shochen betsiyon, The Lord Dwelleth in Zion.
Both point out the continued indwelling of Christ among his people.
Commentary on the Bible, by Adam Clarke [1831].