Surely, &c. These six verses (19-24) are not an "interpolation". They are required to complete the Structure. See above.
Thou wilt slay, &c. This is Omnipotent work. Compare Job 40:9-14.
the wicked. a lawless one. Hebrew. rasha', App-44.
GOD. Hebrew Eloah. App-4.
bloody. blood thirsty.
men. Hebrew. 'enosh. App-14.