“….even at night his mind does not rest. This too is vanity.”
I have said in previous post how I struggle with anxiety and worry at times. Awhile back I realized this is my biggest sin and it overcomes my life sometimes. This verse describes a restless mind as vanity. We all think of vanity as appearance oriented, but by definition it is self absorption. If you are constantly worrying, you are self absorbed in your thoughts and what others think.