1)
When will his mouth be full of Hashem's praise?
1.
Radak: When He will save him.
2.
Malbim: Always. I did not attribute any praise to myself; I attribute all my Gevurah and success to You.
2)
What is "Tif'artecha"?
1.
Radak: I glorify myself in You, that You save me.
2.
Malbim: They are absolute wonders in which You are glorified.