LXX Gen 4:9

καὶ εἶπεν ὁ θεὸς πρὸς Κάιν Ποῦ ἐστιν Ἅβελ ὁ ἀδελφός σου; ὁ δὲ εἶπεν Οὐ γινώσκω· μὴ φύλαξ τοῦ ἀδελφοῦ μού εἰ μί’ ἐγώ;

And the LORD said to Cain, “Where is your brother Abel?” “I do not know!” he answered. “Am I my brother’s keeper?”