And he turn away his wrath from him - Wrath is here taken for the effect of wrath, punishment; and the meaning must be as paraphrased above - lest he take the punishment from him, and inflict it upon thee. And in this way Coverdale understood it: "Lest the Lorde be angry, and turn his wrath from him unto thee." Or we may understand it thus: Lest the Lord inflict on thee a similar punishment; for if thou get into his spirit, rejoicing in the calamities of another, thou deservest punishment.
See the margin. The meaning is “Thy joy will be suicidal, the wrath of the righteous Judge will be turned upon thee, as the greater offender, and thou wilt have to bear a worse evil than that which thou exultest in.”