Origen — as excerpted in the Catena Aurea on Luke 1:1-4

“It is plain that of one kind of knowledge, the end is in the knowledge itself, as in geometry; but of another kind, the end is counted to be in the work, as in medicine; and so it is in the word of God, and therefore having signified the knowledge by the words were themselves eyewitnesses, he points out the work by what follows, and were ministers of the word.”