What is the meaning of "Salisa"?
Rashi: You trampled; You put them to be trampled, like "Silah Chol Abirai" (Eichah 1:15).
Radak: It is a request to trample; the past tense is used in place of future (this is common in Nevu'ah).
Who are "Shogim"?
Radak: They are Resha'im who pretend to be virtuous. When their sins are revealed, they say that they were Shogeg.
Malbim: Shegi'ah is an error in investigation. They do not fulfill Your Chukim because they err. They hold that we need not fulfill Chukim (or deny what oral Torah expounds).
Why does it say "Ki Sheker Tarmisam"?
Radak: They cover themselves, and show themselves to be good, and [really] they are evil. Their deception is revealed; it is found that their way is Sheker.
Malbim: This deception, via their investigations and reasoning, is Sheker.
