Charles H. Spurgeon on Psalms 39:11

When thou with rebukes dost correct man for iniquity. God does not trifle with his rod; he uses it because of sin, and with a view to whip us from it; hence he means his strokes to be felt, and felt they are. Thou makest his beauty to consume away like a moth. As the moth frets the substance of the fabric, mars all its beauty, and leaves it worn out and worthless, so do the chastisements of God discover to us our folly, weakness, and nothingness, and make us feel ourselves to be as worn out vestures, worthless and useless. Beauty must be a poor thing when a moth can consume it and a rebuke can mar it. All our desires and delights are wretched moth eaten things when the Lord visits us in his anger. Surely every man is vanity. He is as Trapp wittily says "a curious picture of nothing." He is unsubstantial as his own breath, a vapour which appeareth for a little while, and then vanisheth away. Selah. Well may this truth bring us to a pause, like the dead body of Amasa, which, lying in the way, stopped the hosts of Joab.