Psalms 64:8

“So shall they make their own tongue to fall upon themselves, etc.] The evil things they have wished for, threatened unto, and imprecated on others, shall come upon themselves; the curses they have cursed others with shall come upon themselves; the pit they have dug for others, they fall into. So Haman, to whom some apply the psalm, was hanged on the gallows he made for Mordecai; and the accusers of Daniel, to whom others apply it, were cast into the same den of lions they procured for him; and Babylon, who has been drunk with the blood of the saints, shall have blood given her to drink. all that see them shall flee away; not being able to help them, nor to bear the horrible sight, and…”

“their . . . tongue to fall, &c.--that is, the consequences of their slanders, &c. (compare Psa 10:2; Psa 31:16). all that see . . . away--Their partners in evil shall be terrified.”

“So they shall make their own tongue to fall upon themselves - In Psalms 64:3, their tongue is represented as a sword; and here, keeping up the figure, the tongue, as a sword, is represented as falling on them, or as inflicting the wound on themselves which they had intended to inflict on others. This might be rendered, “And they have cast him down; upon them is their own tongue;” or, “Upon them their own tongue has come.” That is, someone would cast them down, and they would fall as if smitten by their own tongue like a sword. It is not said who would do this, but the most natural interpretation is that it would be done by God. The idea is, that the instrument which they had employed to…”

“Flee - Through fear of being involved in their destruction. Psalms 64:10”

“tongue: Psa 59:12, Psa 140:9; Job 15:6; Pro 12:13, Pro 18:7; Mat 21:41; Luk 19:22 all that: Psa 31:11, Psa 52:6; Num 16:34; Sa1 31:3-7; Nah 3:7; Rev 18:4, Rev 18:10 Psalms 64:9”