Psalm 32:9

Be ye not as the horse, [or] as the mule, [which] have no
understanding
The design of this exhortation is to direct men how to behave under the instructions given; not as brutes, which have no rational faculties, but as men; that they should not show themselves thoughtless, stupid, and unteachable, as these animals, or worse than they; nor stubborn and obstinate, refractory and untractable, resolving not to be taught, stopping the ear, and pulling away the shoulder; nor ill natured and mischievous; not only hating instruction, casting away the law of the Lord, but kicking and spurning at, and persecuting such who undertake to instruct them; as these creatures sometimes attempt to throw their riders, and, when down, kick at them;

whose mouth must be held in with bit and bridle, lest they come near
unto thee;
to do mischief, bite or kick; or "because they do not come near to thee" ^F20; and that they may come near, and be brought into subjection, and become obedient; therefore such methods are used; see ( James 3:3 ) ; there is in the words a tacit intimation, that men are commonly, and for the most part, like these creatures, stupid, stubborn, and mischievous; and therefore severe methods are used by the Lord, sore chastenings, to humble and instruct them; see ( Jeremiah 31:18 Jeremiah 31:19 ) ; the mule, more especially, is remarkable for its stupidity ^F21; and though the horse is docile, yet he is sometimes stubborn and refractory.