Theophylact of Ohrid — as excerpted in the Catena Aurea on Mark 8:27-33

“He confesses indeed that He is the Christ announced by the Prophets; but the Evangelist Mark passes over what the Lord answered to his confession, and how He blessed him, lest by this way of relating it, he should seem to be favouring his master Peter; Matthew plainly goes through the whole of it.”