Schoftim 5:1 Kommentar: Metzudat David, Metzudat Zion, Radak & Midrash Lekach Tov

Saying: That is to say that the Children of Israel will say it.

From the language of Song

And Devorah and Barak son of Avinoam sang: Because Devorah is the central actor [she is mentioned first]. It is like (Numbers 12:1), "Miriam and Aharon spoke about Moshe."