1)
Who says "Ana Hashem Hoshi'ah Na"?
1.
Pesachim 119a: David's brothers said this when he was anointed.
2.
Radak: Yisrael will say it [in the future].
3.
Malbim: All pray that Hashem save us from oppressors.
2)
Why does it say "Ana Hashem Hatzlichah Na"?
1.
Radak: This is for all who come to take shelter in Your shade and return to Your service.
2.
Malbim: This is a Tefilah that they succeed in all their deeds, from now and forever.
