Matthew 12:18

“I will put my Spirit upon him, And he will declare judgment to the nations (Gentiles).”

He is the One on Whom the Spirit has come in accordance with Matthew 3:11, as witnessed to in Matthew 3:16, being led by the Spirit from then on (Matthew 4:1). But this is no ordinary anointing, for, as we learned in Matthew 3:11, by it He became the One Who could dispense the Spirit. The Spirit will work in accordance with His will. And by casting out evil spirits by that same Spirit He has demonstrated that the Kingly Rule of God has now come (Matthew 12:28). Thus do we learn that the ability of the Apostles to cast out evil spirits (Matthew 10:1) has come through the work of the Spirit on them, as promised in Matthew 3:11. And as a result He will declare righteous truth to the nations (as described in the comments on Matthew 12:18 a).

The word ‘judgment’ includes both the thought of bringing righteous truth to the nations, and also judgment (but still as righteous truth) for those who are under condemnation (Matthew 11:20-24; Matthew 12:41-42). This will finally result in His sending out of His Apostles to the nations (Matthew 24:14; Matthew 28:19).