Bridges on Proverbs 20:2
Charles Bridges on Proverbs 20:2

2.  The fear of a king is as the roaring of a lion: whoso provoketh him to anger sinneth against his own soul.
The wrath of the king has been before mentioned under this figure. (Chapter 19:12.) Here his fear is described, the effect for the cause. Even Joab with all his valor, trembled at this roaring of the lion, and fled for refuge to the horns of the altar.† Jonathan felt the strong necessity for appeasing it.† Such was the power of the king (unknown in our happy land) the sole, the uncontrolled arbiter of life and death;† whosoever therefore provoked him to anger, sinned, as Adonijah found to his cost (1 Kings 2:23), against his own soul. What must then be the fear of the Great King! ‘Armies of terrors and doubts are nothing to a look of his angry countenance. “O LORD,” says that holy man (concerning the frailty of poor man, and the power of God) “who knoweth the power of thine anger? According to thy fear, so is thy wrath.”’† Even “a little kindling” is ruin past conception, and without remedy. (Psalm 2:12.) Nay — his very “enduring long-suffering,” kindles the fire more fiercely for “the vessels of wrath,” whose aggravated provocations of it have “fitted them for destruction.” (Romans 9:22.) ‘Miserable sinner! deprecate his wrath. Seek a Mediator. Beware of continuing in sin.’†