1)
What is "Muzar"?
1.
Radak: This is Mufal, from Zar; they consider me to be a stranger.
2.
Malbim: It is a foreigner.
2)
Who is "l'Echai"?
1.
Rashi: It is Esav 1 .
2.
Radak: They are Bnei Yishmael; Bnei Imi are Bnei Esav.
3.
Malbim: They are Bnei Beisecha (Yisraelim) who do not heed Your voice. (Hashem with Yisrael is like a father with his household.) I quarreled with them about this
1
Surely Rashi means Bnei Esav, similar to Radak's Perush. (PF)