To execute judgment upon all, and to convince all that are ungodly among them of all their ungodly deeds which they have ungodly committed, and of all their hard speeches which ungodly sinners have spoken against him.
Enoch's prophecy is in Hebrew poetic parallelism, the oldest specimen extant. Some think Lamech's speech, which is in poetic parallelism, was composed in mockery of Enoch's; as Enoch foretold Yahweh's coming to judgment, so Lamech presumes on impunity in polygamy and murder (as Cain the murderer seemed to escape).
Convince - convict.
Hard speeches - noticed in Jude 1:8; Jude 1:10; Jude 1:16; Malachi 3:13-14: contrast Jude 1:17-18.
Ungodly sinners - not merely sinners, but х asebeis (G765)] despisers of God: impious.
Against him. They who speak against God's children speak against God Himself.