What is the meaning of "Yerad Sarid l'Adirim"?
Rashi: The remnant of Yisrael flattened the mighty of the nations. Yerad is like "Lerad Lefanav Goyim" (Yeshayah 45:1).
Malbim: This refers to Ehud, who escaped from Mo'av after killing Eglon. (The Shirah contrasts his natural victory to the current victory.)
Why does it say l'Adirim with a Lamed?
Radak: L'Adirim is like b'Adirim. We find that a Lamed is in place of a Beis, e.g. "va'Yeshvu Ito la'Aretz" (Iyov 2:13), "Ish Haragti l'Fitz'i" (Bereishis 4:23).
Malbim: [Ehud defeated Mo'av, i.e. weak remnants] due to Adirim who helped him - "va'Yiska ba'Shofar... v'Yerdu Imo Vnei Yisrael" (3:27).
What is the meaning of "Hashem Yerad Li ba'Giborim"?
Rashi: Hashem flattened for me the mighty nations.
Malbim: I [Devorah] am different. I did not defeat the enemy myself, or with Adirim, rather, Hashem alone. And this was not a weak remnant, rather, Giborim (Sisera's army).
