12 “When he speaks a lie, he speaks of his own: for he is a liar, and the father of it.” What is this? You have heard the words of the Gospel: you have received them with attention. Here now, I repeat them, that you may clearly understand the subject of your thoughts. The Lord said those things of the devil which ought to have been said of the devil by the Lord. That “he was a murderer from the beginning” is true, for he slew the first man; “and he abode not in the truth,” for he lapsed from the truth.
“When he speaks a lie,” to wit, the devil himself, “he speaks of his own;” for he is a liar, and its [his] father. From these words some have thought that the devil has a father, and have inquired who was the father of the devil. Indeed this detestable error of the Manicheans has found means down to this present time wherewith to deceive the simple. For they are wont to say, Suppose that the devil was an angel, and fell; and with him sin began as you say; but, Who was his father?
We, on the contrary, reply, Who of us ever said that the devil had a father? And they, on the other hand, rejoin, The Lord says, and the Gospel declares, speaking of the devil, “He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaks a lie, he speaks of his own: for he is a liar, and his father.”
Source: Tractates on the Gospel of John (New Advent)