Why does it say "Becha Tzar'einu Nenage'ach"?
Radak: With Your help, we will gore our enemies. "Nenage'ach" is like "Bahem Amim Yenagach Yachdav" (Devarim 33:17).
Malbim: If You will not do for us like in days of old, that we did not need war at all, at least the war should be via Your help; trampling our enemies will be via You.
Why does it say "b'Shimcha"?
Malbim: If also this (You Yourself helping us in war) You will not do, at least with Your name we should trample our enemies - send help in Your name - an angel coming in Your name.
What is the meaning of "Navus Kamenu"?
Rashi: We will trample our enemies. "Navus" is like "Misboseses b'Damayich" (Yechezkel 16:6). Radak - "Kamenu" is like Tzar'einu; they rise against us for evil.
Malbim: [Even if we will not trample all our enemies, at least] we will trample those who rise against us.
