Theophylact of Ohrid
Catena Aurea · Markusevangelium 1
(Mal. 3:1) As it is written in the Prophets, Behold, I send my messenger before thy face, which shall prepare thy way before thee. The voice of one crying in the wilderness, (Isa. 40:3) Prepare ye the way of the Lord, make his paths straight.
Or, the way is the New Testament, and the paths are the Old, because it is a trodden path. For it was necessary to be prepared for the way, that is, for the New Testament; but it was right that the paths of the Old Testament should be straightened.