Albert Barnes Commentary Ezekiel 36:38

"As the flock for sacrifice, as the flock of Jerusalem in her appointed feasts, so shall the waste cities be filled with flocks of men; and they shall know that I am Jehovah." — Ezekiel 36:38 (ASV)

As the holy flock - A reference to the flocks and herds brought up to Jerusalem to be consecrated and offered to the Lord (2 Chronicles 35:7). Thus, the idea is brought out:

1. Of the multiplication of the people,
2. Of their dedication to the service of God.