LXX Gen 1:6

Καὶ εἶπεν ὁ θεός Γενηθήτω στερέωμα ἐν μέσῳ τοῦ ὕδατος, καὶ ἔστω διαχωρίζον ἀνὰ μέσον ὕδατος καὶ ὕδατος· καὶ ἐγένετο οὕτως.

And God said, “Let there be an expanse between the waters, to separate the waters from the waters.”