What is "Tola'as Yakov"?
Rashi (from Yelamdenu): The family of Yakov is weak like a worm; its only strength is in its mouth. Radak - a worm is soft, and it strikes (breaks) hard cedars. So Yisrael, their entire strength is in Tefilah, and they strike Resha'im strong like cedars. They are compared to "Erez ba'Levanon" (Yechezkel 31:3, i.e. Ashur).
Radak: They are weak in Galus, like a worm.
Malbim: Yakov, the commoners, are compared to a rotting Mes.
What are "Mesei Yisrael"?
Rashi: It is the number of Yisrael.
Radak: "Mesei" are the people of.
Malbim: Yisrael, the esteemed of the nation and the Giborim, it is as if only Mesim and weak people remain. Even so, do not fear!
Why does it say "Azartich" (feminine)?
Radak: It refers to Tola'as, even though it says "Mesei".
Why does it say "Hashem v'Go'alech Kedosh Yisrael"?
Malbim: One does not rely on a helper if (a) the helper is weak. Hashem, the Master of power and ability, helps you! (b) One does not rely on a helper if he might not want to help. I am Go'alech, called Kedosh Yisrael due to your Kedushah and deeds. You deserve salvation!
