77 In good truth, I must repeat here once more an admonition which it behooves the reader to keep in mind, so as not to be requiring that kind of advice so very frequently, namely, that in various passages of His discourses, the Lord has reiterated much which He had uttered already on other occasions. It is needful, indeed, to call this fact to mind, lest, when it happens that the order of such passages does not appear to fit in with the narrative of another of the evangelists, the reader should fancy that this establishes some contradiction between them; whereas he ought really to understand it to be due to the fact that something is repeated a second time in that connection which had been already expressed elsewhere. And this is a remark that should be held applicable not only to His words, but also to His deeds. For there is nothing to hinder us from believing that the same thing may have taken place more than once. But for a man to impeach the gospel simply because he does not believe in the repeated occurrence of some incident, which no one [at least] can prove to be an impossible event, betrays mere sacrilegious vanity.
Source: The Harmony of the Gospels (New Advent)