John Gill Commentary Psalms 36:12

"There are the workers of iniquity fallen: They are thrust down, and shall not be able to rise." — Psalms 36:12 (ASV)

There are the workers, of iniquity fallen
Either in the pit they dug for others; or into hell, where they shall be turned at last; (See Gill on Psalms 5:5) and (See Gill on Psalms 6:8);

they are cast down, and shall not be able to rise ;
which will be the case of Babylon when fallen, (Revelation 18:21) , and this distinguishes the falls of the wicked from those of the righteous; for though the righteous fall, whether into sin, or into any calamity, they rise again; not so the wicked; see (Psalms 37:24) (Micah 7:8) ; and thus, as the psalm begins with the transgression of the wicked, it ends with their ruin.