Genesis 48:5

5. Furthermore, as to those critics who find a difficulty in the circumstance that Matthew enumerates one series of ancestors, beginning with David and travelling downwards to Joseph, while Luke specifies a different succession, tracing it from Joseph upwards as far as to David, they might easily perceive that Joseph may have had two fathers, namely, one by whom he was begotten, and a second by whom he may have been adopted. For it was an ancient custom also among that people to adopt children with the view of making sons for themselves of those whom they had not begotten. …

28. And let not the law of adoption seem to you to be foreign to our Scriptures, and that, as if it were recognised only in the practice of human laws, it cannot fall in with the authority of the divine books. For it is a thing established of old time, and frequently heard of in the Ecclesiastical books, that not only the natural way of birth, but the free choice of the will also, should give birth to a child. For women, if they had no children of their own, used to adopt children born of their husbands by their hand-maids, and even oblige their husbands to give them children in this way; as Sarah, Rachel, and Leah. …

What this is, observe. One of the twelve sons of Jacob was Joseph.…This Joseph had two sons, Ephraim and Manasse. Jacob, dying, as though by will, received those his grandsons into the number of sons, and said to his son Joseph, “The rest that are born shall be to thee; but these to me, and they shall divide the land with their brethren.” As yet there had not been given nor divided the land of promise, but he was speaking in the Spirit, prophesying. The two sons therefore of Joseph being added, there were made up nevertheless twelve tribes, since now there are thirteen. For instead of one tribe of Joseph, two were added, and there were made thirteen. There being taken out then the tribe of Levi, that tribe of priests which did serve the Temple, and lived by the tithes of all the rest unto whom the land was divided, there remain twelve. …

4. As then, when we read this, we interpret it fairly, without accounting Solomon a servant because we hear him so called, but a son natural and genuine, so also, if, concerning the Saviour, who is confessed to be in truth the Son, and to be the Word by nature, the saints say, ‘Who was faithful to Him that made Him,’ or if He say of Himself, ‘The Lord created me,’ and, ‘I am Thy servant and the Son of Thine handmaid,’ and the like, let not any on this account deny that He is proper to the Father and from Him; but, as in the case of Solomon and David, let them have a right idea of the Father and the Son. …