Parallel
Deuteronomy 21:17
Rahlfs Septuagint (1935) · Berean Standard Bible
ἀλλὰ τὸν πρωτότοκον υἱὸν τῆς μισουμένης ἐπιγνώσεται δοῦναι αὐτῷ διπλᾶ ἀπὸ πάντων ὧν ἂν εὑρεθῇ αὐτῷ ὅτι οὗτός ἐστιν ἀρχὴ τέκνων αὐτοῦ καὶ τούτῳ καθήκει τὰ πρωτοτόκια
Instead, he must acknowledge the firstborn, the son of his unloved wife, by giving him a double portion of all that he has. For that son is the firstfruits of his father’s strength; the right of the firstborn belongs to him.