Why did he say "Tastirem"?
Radak #1: It is a Tefilah.
Radak #2: It was said via Nevu'ah.
Malbim: Even though sometimes it looks like Hashem hides His face from those who fear Him, and via this they have evils in this world, this is for their benefit. Via hiding His face, he hides them from Ruchsei Ish (refer to 31:21:3:3).
What is "b'Seser Panecha"?
Radak: It is the hidden part of Your desire. When He turns to a person, He desires him; when He hides His eyes from him, He hates him - "Oref v'Lo Panim Er'em b'Yom Eidam" (Yirmeyah 18:17).
Malbim: Even when You hide Your face, You save [those who trust in You] from slanderers 1 , just like He saved David from Zifim and those who slandered him in front of Sha'ul.
Achimelech died via Do'eg's slander! Perhaps it was his time to die; Hashem protects those who trust in Him from premature death due to slanderers. (PF)
What are "Ruchsei Ish"?
Rashi: They are bands of Resha'im who band together to do evil to [those who trust in Hashem].
Radak: It is people's haughtiness and highness, like it says "b'Ga'avah va'Vuz" (verse 19). This is like "va'Yirchesu Es ha'Choshen" (Shemos 28:28), which is like 'they lifted.'
Malbim: They are snags in a person's nature, e.g. the Yetzer ha'Ra and lusts, which are like hills that ruin the straight path. They block a person from going straight. Via Hester Panim and affliction, the crooked becomes straight and the hills become a valley, and they can go on a straight path.
What is "me'Riv Leshonos"?
Radak: This is like "Dibas Rabim", "ha'Dovros Al Tzadik Asak" (verses 14, 19).
