John Trapp on Proverbs 4:19

Verſ. 19. Is as darkneſs] That little light they had by nature they impriſon, [non-Latin text not transcribed]. Rom. 1.18. Rom. 1. and are juſtly deprived of. And as for thoſe ſparkles of the light of joy and comfort that hypocrites have, it is but as a flaſh of lightning which is followed with a thunder-clap, or like the light ſmitten out of the flint: firſt, they cannot warm themſelves by it, not ſee to direct their waies. 2. It will quickly go out. 3. And after that, they muſt lye down in ſorrow, Iſa. 50.10.

They know not at what they ſtumble] They ſtumble ſometimes at Chriſt himſelf, 1 Pet. 2.8. and at his word, being diſobedient; whereunto alſo they were appointed. A ſhrewd ſign of reprobation. The Vulgar renders it, Ne ſciunt ubi corruant, They know not how ſoon they may drop into Hell, which even gapes for them, Iſa. 29.33.