Job 39:11

Wilt thou trust him? -As thou dost the ox. In the domestic animals great confidence is of necessity placed, and the reliance on the fidelity of the ox and the horse is not usually misplaced. The idea here is, that the unicorn could not be so tamed that important interests could be safely entrusted to him. Because his strength is great? -Wilt thou consider his strength as a reason why important interests might be entrusted to him? The strength of the ox, the camel, the horse, and the elephant was a reason why their aid was sought by man to do what he could not himself do. The idea is, that man could not make use of the same reason for employing the rhinoceros.