Parallel
Genesis 38:9
Swete's Septuagint · Berean Standard Bible
γνοὺς δὲ Αύνὰν ἣτι οὐκ αὐτῷ ἔσται τὸ σπέρμα, ἐγίνετο, ὃταν εἰσήρχετο πρὸς τὴν γυναῖκα τοῦ ἀδελφοῦ αὐτοῦ, ἐξέχεεν ἐπὶ τὴν γῆν τοῦ μὴ δοῦναι σοέρνα τῷ ἀδελφῷ αὐτοῦ.
But Onan knew that the offspring would not belong to him; so whenever he would sleep with his brother’s wife, he would spill his seed on the ground so that he would not produce offspring for his brother.