John Wesley on Isaiah 8:18

Behold - These words are literally spoken by Isaiah concerning himself, but mystically concerning Christ; and therefore they are fitly ascribed to Christ, Heb 2:13. The children - His spiritual children, whom he had either begotten or brought up by his ministry. Wonders - Are a gazing flock, for our folly in believing God's promises. From the Lord - Which comes to pass by the wise providence of God. Zion - Where the temple now was, and where the Messiah was to set up his kingdom.