Ambrose of Milan
Catena Aurea · Lukasevangelium 1
For he shall be great in the sight of the Lord, and shall drink neither wine nor strong drink; and he shall be filled with the Holy Ghost, even from his mother’s womb. And many of the children of Israel shall he turn to the Lord their God. And he shall go before him in the spirit and power of Elias, to turn the hearts of the fathers to the children, and the disobedient to the wisdom of the just; to make ready a people prepared for the Lord.
For never is the spirit without power, nor power without the spirit. And therefore it is said, in the spirit and power; because holy Elijah had great power and grace. Power, so that he turned back the false hearts of the people to faith; power of abstinence, and patience, and the spirit of prophecy. Elijah was in the wilderness, in the wilderness also was John. The one sought not the favour of king Ahab; the other despised that of Herod. The one divided Jordan; the other brought men to the Saving waters; John, the forerunner of our Lord’s first coming; Elijah of His latter.