Shall they escape by iniquity? in thine anger cast down the people, O God.
Shall they escape by iniquity? - literally, 'upon (the ground of) their iniquity (there is) to them (the hope of) escape' (cf. Isaiah 28:15). Such was Saul's vain hope of averting, by the persecution of David, God's sentence that he should lose his throne.
In thine anger cast down the people - `the peoples' who plot with Saul against me. So the parallel, Psalms 7:6.