LXX Gen 17:12

καὶ παιδίον ὀκτὼ ἡμερῶν περιτμηθήσεται ὐμῖν πᾶν ἀρσενικὸν εἰς τὰς γενεὰς ὑμῶν· ὁ οἰκογενὴς τῆς οἰκίας σου καὶ ὁ ἀργυρώνητος ἀπὸ παντὸς υἱοῦ ἀλλοτρίου, ὄς οὐκ ἔστιν ἐκ τοῦ σπέρματός σου,

Generation after generation, every male must be circumcised when he is eight days old, including those born in your household and those purchased from a foreigner—even those who are not your offspring.