Adam Clarke on Psalms 58:9

Before your pots can feel the thorns - Ye shall be destroyed with a sudden destruction. From the time that the fire of God's wrath is kindled about you, it will be but as a moment before ye be entirely consumed by it: so very short will be the time, that it may be likened to the heat of the first blaze of dry thorns under a pot, that has not as yet been able to penetrate the metal, and warm what is contained in it.

A whirlwind - Or the suffocating simoon that destroys life in an instant, without previous warning: so, without pining sickness - while ye are living - lively and active, the whirlwind of God's wrath shall sweep you away.