Answers for a Jew
Why do the Gospels contain two genealogies of Joseph? (ending)
At the end of the same letter, Africanus adds: "Matthan, a descendant of Solomon, begat Jacob. After the death of Matthan, Melki [Matthat], a descendant of Nathan, begat Heli by the same woman. Therefore, Heli and Jacob must be uterine brothers. Heli died childless; Jacob raised up his seed by begetting Joseph who was his son according to the flesh, and Heli's son according to the Law. So, we can say that Joseph was the son of them both".
This is the testimony of Afrikanus. If such was the genealogy of Joseph, then Mary had to be from the same tribe, for, according to the Law, it wasn't allowed to marry outside your tribe. The Law said that a man should take a wife out of the same town and the same family so that the inheritance would not go from one tribe to another. With this let us end» (The History of the Church, 1,7).
The explanation offered by Africanus is correct, though he confused Melki with Matthat. The genealogy in Matthew lists births according to the flesh; the one in Luke is according to the Law. It must be added that the levirate links between the two genealogies are found not only at the end, but also in the beginning. This conclusion is obvious because both genealogies intersect in the middle at Zerubbabel, son of Shealtiel (see Mt 1:12-13; Lk 3:27). Nathan was the older brother; Solomon was younger, next in line after him (see 2 Sam 5:14-16; 1 Cron 3:5), therefore he was the first candidate to a levirate marriage (compare Ruth 3-4; Lk 20:27-33). The Old Testament is silent on whether Nathan had children, so we may very well conclude that he had none. Solomon, however, had much capacity for love: «And he had seven hundred wives, princesses, and three hundred concubines» (1 Kings 11:3). So, in theory, he could have married Nathan's widow. If this is so, Mattatha is the son of Solomon according to the flesh and the son of Nathan according to the Law. In light of the above-mentioned circumstances, the differences between the two genealogies no longer present a problem.
(to be continued)