That say, Let him make speed, and hasten his work, that we may see it: and let the counsel of the Holy One of Israel draw nigh and come, that we may know it!
That say, Let him make speed, (and) hasten his work - vengeance (Isaiah 5:12). Language of defiance to God. So Lamech's boast of impunity (Genesis 4:23-24: cf. Jeremiah 17:15; 2 Peter 3:3-4).
Let the counsel of the Holy One of Israel draw nigh and come - God's threatened purpose to punish.
That we may know it. They deny all knowledge which is matter of faith, and cannot be demonstrated to the senses