Origen In Jn., 20.3, 10

Bk 20.3

So that these things may be perceived, then, let us first see the difference between “seed” and “child” in the literal sense.  Now it is clear that the seed of someone has the principles of the procreator in itself still at rest and reserved.  The child exists, however, once it has been formed and prepared for birth, when seed has been transformed and has molded the material surrounding it provided by the woman and the collected nourishments.  And if some portion [of seed] is someone’s child in the proper sense [of the word “child”], as in the case of physical children, it exists from seed, but if something is seed, it does not necessarily become a child.

Bk 20.10 etc.

We will reply to these objections by using the literal sense as a ladder, as it were, and seeking the traces of the truth in the letters of the passage.  If someone who is not a child of Abraham were seed of no just man, he would be blameless even if he were a sinner because he would have no opportunity for doing good from his seeds. But, as it is, just as in the case of physical bodies, one is seed of numerous just men and another if fewer, as will be clear from the comparison if the things that we will relate, so it will be possible to say the equivalent in the case if the anagogical sense.

11. Abraham was born the twentieth form the first formed man, for there were ten generations from Adam to Noah, and ten from Noah to Abraham. And Abraham’s brothers were Nachor and Aran, for the three were sons of Thare. Nachor and Aran, therefore, were not seed of Abraham. Not even Abraham himself was seed of Abraham.

12. The three however were seed of just men. Consequently, if the just men descended from Adam are further investigated, among which of them must Abraham be numbered? He was seed of Seth whom God raised up in place of Abel; and if Enos who “hoped to call upon the name of the Lord God”; and of Henoch, “who was well-pleasing to God two hundred years after he begat Mathusda”; and Noah, of whom it is said, “A just man, perfect in his generation; Noah was well-pleasing to God”; and of Sem, whose God appears first to have called, “the Lord God,’ ub Genesis, which is clear from the statement, “Blessed be the Lord God of Sem.” These three sons if Thare, however, were the seed of the rest [of Adam’s descendants] in addition to these.