Albert Barnes Commentary Psalms 56:7

"Shall they escape by iniquity? In anger cast down the peoples, O God." — Psalms 56:7 (ASV)

Shall they escape by iniquity? - This expression in the original is very obscure. There is in the Hebrew no mark of interrogation; and a literal rendering would be, “By iniquity (there is) escape to them.” According to this, the sense would be that they contrived to escape from just punishment by their sins, by the boldness of their crimes, and by their wicked arts.

The Septuagint renders it, “As I have suffered this for my life, you will on no account save them.” Luther states, “What they have done evil, that is already forgiven.” DeWette reads it, as in our translation, as a question: “Shall their deliverance be in wickedness?”

Probably this is the true idea. The psalmist asks with earnestness and amazement whether, under the divine administration, people “can” find safety in mere wickedness, whether great crimes constitute an evidence of security, or whether his enemies owed their apparent safety to the fact that they were so eminently wicked.

He prays, therefore, that God would interfere and show that this was not, and could not be so.

In thine anger cast down the people, O God - That is, show by your own interposition—by the infliction of justice, by preventing the success of their plans, and by discomfiting them—that under the divine administration wickedness does not constitute security.

In other words, show that you are a just God and that wickedness is not a passport to your favor.