Adams on Psalm 32:9

9. Be ye not as the horse, or as the mule, etc. How many run mad of this cause, inordinate and furious lusts! The prophet Jeremiah, Jer 2:24, compares Israel to "a swift dromedary, traversing her ways," and to "a wild ass used to the wilderness, that snuffeth up the wind at her pleasure." Be ye not, said the psalmographer, "as the horse, or as the mule, which have no understanding: whose mouth must be held in with bit and bridle." Men have understanding, not beasts; yet when the frenzy of lust overwhelms their senses, we may take up the word of the prophet and pour it on them: "Every man is a beast by his own knowledge." And therefore "man that is in honour and understandeth not, is like unto beasts that perish" Ps 49:20. Did not the bridle of God's overruling providence restrain their madness, they would cast off the saddle of reason, and kick nature itself in the face.

As quoted in Spurgeon's Treasury of David.