Origen
Catena Aurea · Lukasevangelium 1
Forasmuch as many have taken in hand to set forth in order a declaration of those things which are most surely believed among us, Even as they delivered them unto us, which from the beginning were eyewitnesses, and ministers of the word: It seemed good to me also, having had perfect understanding of all things from the very first, to write unto thee in order, most excellent Theophilus, That thou mightest know the certainty of those things, wherein thou hast been instructed.
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.