Bamidbar 16:8

ויאמר משה אל קרח שמעו נא בני לוי AND MOSES SAID UNTO KORAH, HEAR, I PRAY YOU, YE SONS OF LEVI — He began to speak to him with gentle words; when, however, he saw that he was stubborn, he said to himself: Before the other tribes join him and perish together with him, I will speak to them all!” He thereupon began to admonish them: “Hear ye, ye sons of Levi!” (Midrash Tanchuma, Korach 6).

וַיֹּ֥אמֶר מֹשֶׁ֖ה אֶל־קֹ֑רַח שִׁמְעוּ־נָ֖א בְּנֵ֥י לֵוִֽי׃

And Moshe said to Qoraĥ, Hear, I pray you, sons of Levi: