Psalms 32:9 - Joseph Benson’s Commentary on the Old and New Testaments

Be not as the horse, or as the mule God hath endowed you with reason, both to inform you what you ought to do. and to check you when you do amiss, and hath made you capable also of receiving good admonitions from others; do not therefore follow your own unbridled lusts and appetites; much less be refractory and untractable, when God would reduce you from the error of your ways; as if you were not men, but headstrong horses and mules, which can by no means be curbed or governed, without bit and bridle. Houbigant renders the last clause, very properly, Or they will not come near thee; for, as horses and mules are not dangerous beasts, whose common practice it is to kick or bite, the word lest is extremely improper. Nor is it the proper use of a bit, or bridle, to keep them from so doing, but rather to bring them nearer to the rider, for his use, and to keep them under his power and management.