“That is not all.
Happened to Rebecca,
When she had conceived children
By one husband,
Our ancestor Isaac.”
οὐ μόνον δέ, ἀλλὰ καὶ Ῥεβέκκα ἐξ ἑνὸς κοίτην ἔχουσα, Ἰσαὰκ τοῦ πατρὸς ἡμῶν
Paul said that is not all (οὐ μόνον δέ). Something similar happened to Rebecca (ἀλλὰ καὶ Ῥεβέκκα), when she conceived twin children by one husband (ἐξ ἑνὸς κοίτην ἔχουσα), our ancestor Isaac (Ἰσαὰκ τοῦ πατρὸς ἡμῶν). Next Paul moved on to the children of Isaac and Rebecca, the story of the twins Esau and Jacob, as found in Genesis, chapters 25:19-27:45. Paul simply said that the Rebecca story was similar to the Sarah story earlier in Genesis. Rebecca, however, had twin sons from the same person, her husband and their ancestor Isaac. Paul never went into the part of how Jacob tricked his twin brother Esau out of the blessing and inheritance from Isaac. Do you know anyone who is a twin?