1 Paul, a servant of Jesus Christ, a called apostle, having been separated to the good news of God 2 which He announced before through His prophets in holy writings 3 concerning His Son, (having come/γενομένου of the seed/σπέρματος of David according to the flesh, 4 who is marked out Son of God in power, according to the Spirit of sanctification, by the rising again from the dead,) Jesus Christ our Lord; 5 through whom we did receive grace and apostleship, for obedience of faith among all the nations, in behalf of his name; 6 among whom are also ye, the called of Jesus Christ
having come = γενομένου = genomenou - https://biblehub.com/interlinear/romans/3-4.htm - a derivative of ginomai/γίνομαι
Ginomai / γίνομαι
- to become, i.e. to come into existence, begin to be, receive being
- to become, i.e. to come to pass, happen
- of events
- to arise, appear in history, come upon the stage
- of men appearing in public
- to be made, finished
- of miracles, to be performed, wrought
- to become, be made
https://www.biblestudytools.com/lexicon ... nomai.html
Galatians 4:4 uses γενόμενον/genomenon twice
....made. of. a woman ... made .under the law
Throughout the rest of the New Testament ginomai/γίνομαι is never used for birth or born: gennao is, 97 times apparently.
- (ginomai/γίνομαι has occasionally been used for birth or born is other places in Greek writings)
Einar Thomassen asserts in The Spiritual Seed: The Church of the “Valentinians", 2006, that
... a very important principle of Valentinian soteriology must be grasped: when the Saviour descended into the cosmos, he put on as his body, or flesh, the spiritual seed of Sophia. ...
... When the Saviour eventually descended into the cosmos, the spiritual seed constituted his body. Thus they were incarnated concorporeally with the Saviour. [p.30]
She said that in relation to quoting the start of Excerpt from Theodotus (from a set of notes written by Clement of Alexandria preserved in Codex Laurentianus V,3.) thus:
(1:1)
What Sophia brought forth,...as flesh for the Logos,
[was] the spiritual seed/σπέρμα that the Saviour put on when he descended.
(2) ... [the Father] commits the entire spiritual seed/σπέρμα, the elect ...
In other words, the spiritual seed was the flesh the Saviour or Logos [or both] put on when he descended
The same concept appears in Excerpt from Theodotus in 26:1 of their source, a set of notes written by Clement of Alexandria preserved in Codex Laurentianus V,3 :
The visible part of Jesus was Sophia/Wisdom and the έκκλησία of the superior seed/σπερμάττων
which he put on through the flesh, as Theodotus says.
But the invisible part was the Name, which is the only-begotten Son.
In this case, the Saviour’s flesh is Wisdom and the έκκλησία/assemby(?) of the superior spiritual seed (which he put on (στολίζειν, stolizein) when he descended into the world)
One might consider this is a meaning or concept, either in it's entirety or in part, that Paul meant for "His Son having come/been made/γενομένου of the seed/σπέρματος of David according to the flesh" in Romans 1:3, perhaps also in light of Romans 1:4 and 1:6