Ambrose of Milan

But that the Spirit is the Arbiter of the Divine Counsel, you may know even from this. For when above we showed that the Holy Spirit was the Lord of baptism, and read that baptism is the counsel of God, as you read, "But the Pharisees despised the counsel of God, not being baptized of Him," it is quite clear that as there can be no baptism without the Spirit, so, too, the counsel of God is not without the Spirit. And that we may know more completely that the Spirit is Power, we ought to know that He was promised when the Lord said: "I will pour out of My Spirit upon all flesh." He, then, Who was promised to us is Himself Power, as in the Gospel the same Son of God declared when He said: "And I will send the promise of the Father upon you, but do you remain in the city until ye be endued with power from on high."