'Watchmen' in the Bible

The voice of your watchmen! their voices are loud in song together; for they will see him, eye to eye, when the Lord comes back to Zion.

His watchmen are blind, they are all without knowledge; they are all dogs without tongues, unable to make a sound; stretched out dreaming, loving sleep.

I have put watchmen on your walls, O Jerusalem; they will not keep quiet day or night: you who are the Lord's recorders, take no rest,