Gregory the Great — as excerpted in the Catena Aurea on Matthew 11:1-6

“(Aug, ubi sup) But this question may be answered in a better way if we attend to the order of time. At the waters of Jordan he had affirmed that this was the Redeemer of the world after he was thrown into prison, he enquires if this was He that should come—not that he doubted that this was the Redeemer of the world, but he asks that he may know whether He who in His own person had come into the world, would in His own person descend also to the world below.”