Gregory the Great — as excerpted in the Catena Aurea on Mark 1:4-8

“(Moral. xxxi. 25) Or, by the kind itself of his food he pointed out the Lord, of whom he was the forerunner; for in that our Lord took to Himself the sweetness of the barren Gentiles, he ate wild honey. In that He in His own person partly converted the Jews, He received locusts for His food, which suddenly leaping up, at once fall to the ground. For the Jews leaped up when they promised to fulfil the precepts of the Lord; but they fell to the ground, when by their evil works they affirmed that they had not heard them. They made therefore a leap upwards in words, and fell down by their actions.”