Matthew Poole and continuators on Job 41:8

8. Lay thine hand upon him , remember the battel , do no more.

Either, 1. in a familiar and friendly manner, that thou mayest catch him by deceit when thou canst not do it by force. Or rather 2. in way of Hostility, seize upon him and take him by a strong hand, if thou darest do so.

But ere thou do attempt that, consider what thou art doing and how hazardous thy enterprize is, and with whom, and with what disadvantage thou art going to fight, and as it follows, do no more, proceed no further, draw back thy hand, and be thankful for so great a deliverance. Or the Verse may be rendred thus. If (which Particle is oft understood) thou offerest or attemptest to lay violent hands on him thou wilt have cause to remember (the Imperative being put for the Future, which is frequent in the Hebrew Language) the battel, and thou wilt do so no more; If thou doest escape, thou wilt never forget thy danger, nor attempt any thing of like nature for the time to come.