Charles H. Spurgeon on Psalms 119:113

Vain thoughts. Let us see what vanity is. Take it in all the acceptances of it, it is true of our thoughts that they are "vain."

1. It is taken for unprofitableness. So, Ecclesiastes 1:2-3, "All is vain, "because there is "no profit in them under the sun." Such are our thoughts by nature; the wisest of them will not stand us in any stead in time of need, in time of temptation, distress of conscience, day of death or judgment: 1 Corinthians 2:6, "All the wisdom of the wise comes to nought"; Proverbs 10:20. "The heart of the wicked is little worth, "not a penny for them all.

2. Vanity is taken for lightness. "Lighter than vanity, "is a phrase used, Psalms 62:9; and whom is it spoken of? Of men; and if anything in them be lighter than other, it is their thoughts, which swim in the uppermost parts, float at the top, are as the scum of the heart. When all the best, and wisest, and deepest, and solidest thoughts in Belshazzar, a prince, were weighed, they were found too light, Daniel 5:27.

3. Vanity is put for folly. So, Proverbs 12:11, "vain men" is made all one with men "void of understanding." Such are our thoughts. Among other evils which are said to "come out of the heart" (Mark 7:22), afrosunh is reckoned as one, "foolishness"; that is, thoughts that are such as madmen have, and fools nothing to the purpose, of which there can be made no use.

4. Vanity is put for inconstancy and frailty; therefore vanity and a shadow are made synonymous, Psalms 144:4. Such are our thoughts, flitting and perishing, as bubbles: Psalms 144:4, "All their thoughts perish."

5. Lastly, they are wicked and sinful. Vanity is Jeremiah 4:14 yoked with wickedness, and vain men and sons of Belial are all one, 2 Chronicles 8:7. And such are our thoughts by nature: Proverbs 14:9, "The thought of foolishness is sin." And therefore a man is to be humbled for a proud thought. Thomas Goodwin.