Matthew Poole and continuators on Job 20:14

14. Yet his meat in his bowels is turned , it is the gall of asps within him.

Into another nature or quality, from sweet to bitter.

i. e. Exceeding bitter and pernicious. Gall is most bitter; the Gall of Serpents is full of poyson, which from thence is conveyed to their mouths by Veins as Pliny observes; and the poyson of Asps is most dangerous, and within a few hours kills without remedy.