1)
Which brothers are discussed?
1.
Malbim: They are Bnei Edom; we are amidst them in Galus. Also Bnei Yishmael and Bnei Keturah are our brothers; they are from Avraham.
2)
What will he tell?
1.
Radak #1: When you will save me from the lion and the Re'em, i.e. take me out of Galus, I will tell [Your salvations].
2.
Radak #2: We in Galus will tell of Your wonders in the exile of the 10 tribes. They were exiled to Lachlach and Chabor, and the nations did not rule over them, like they rule over us.
