The fear of a king - Almost the same with Proverbs 19:12; (note), which see.
Albert Barnes
Notes on the Whole Bible
Sinneth against his own soul - i. e., Against his own life (compare Habakkuk 2:10).
SDA Bible Commentary (limited)
Volume 1-7
2. Sinneth. One who stirs up the wrath of a king or other despotic ruler is taking his life in his hands and is likely to lose it (see chs.8:36; 19:12).