Charles H. Spurgeon on Psalms 64:8

Their own tongue to fall upon themselves. That is, their own words shall be brought as a testimony against them, and condemn them. "The tongue is a little member" (Jas 3:5), and therefore a light member; yet it falls heavy, as heavy as lead. A man were better have his house fall upon him, than that, in this sense, his tongue should fall upon him. Some have been pressed to death because they would not speak, but stood mute before the judge; but more have been pressed to death by their sinful freedom, or rather licentiousness in speaking; this hath brought them to judgment, and cast them in judgment... A strange thing, that the fall of a man's tongue should oppress his body and whole estate; yet so it is, the weight of a man's tongue falling upon him crushes him to powder. Joseph Caryl.