
Augustine of Hippo
Catena Aurea · Matthäusevangelium 1
So all the generations from Abraham to David are fourteen generations; and from David until the carrying away into Babylon are fourteen generations; and from the carrying away into Babylon unto Christ are fourteen generations.
(De Cons. Ev. ii. 4.) Or, one of Christ’s forefathers is counted twice, because in him, Jeconiah to wit, there was made a passing off to strange nations since he was carried to Babylon. Wherever a series turns out of the right line to go in any other direction there is an angle made, and that part that is in the angle is reckoned twice. Thus here is a figure of Christ, who passes from the circumcision to the uncircumcision, and is made a cornerstone.