LXX Gen 18:26

εἶπεν δὲ κύριος Ἐὰν εὕρω ἐν Σοδόμοις πεντήκοντα δικαίους ἐν τῇ πόλει, ἀφήσω πάντα τὸν τόπον δι’ αὐτούς.

So the LORD replied, “If I find fifty righteous ones within the city of Sodom, on their account I will spare the whole place.”