誣告加三等 False Accusation Three Degrees
且莫說我是天上元勛，封受先斬後奏之職，就是下界小民，也不可誣告。律云：『誣告加三等。』」叫手下：「將縛妖索把這猴頭綑了。」且莫说我是天上元勋，封受先斩后奏之职，就是下界小民，也不可诬告。律云：『诬告加三等。』」叫手下：「将缚妖索把这猴头捆了。」
逐句解 Line by line
Never mind that I am a founding officer of heaven, holding an office that lets me execute first and report afterwards — even a small commoner in the world below cannot be falsely accused.
先斬後奏 is to behead first and memorialise after, the licence given to a very few officials to act without waiting for approval. It is still a live idiom for anybody who does the thing and tells you later. 元勛 is a founding minister, one of the men who were there at the beginning.
The statute says: false accusation, three degrees added."
誣告加三等 is not invented. Ming law punished a false accuser with the penalty he had sought against his victim, increased by three degrees on the sentencing scale — so a man who falsely accused another of a capital crime was in serious trouble indeed. This is the rule Bajie warned about at the start of the and here it is with its statutory name on.
He called to his people, "Take the demon-binding rope and tie this monkey head up."
縛妖索 is the demon-binding rope, standard heavenly equipment. 將 is the disposal marker jiāng, taking the rope and putting it in front of the verb. The Heavenly King has moved from citing the law to using it as a warrant, and that is the mistake.
The Heavenly King's case is legally sound from beginning to end. He is a great officer, the accusation is false, and the statute on false accusation says what he says it says.
Then he arrests the plaintiff in the middle of proceedings, which is where the law stops being on his side. Everything after this happens because a man who was right could not bear to wait to be proved right.