I like some of the ideas some of the others have given.

Giving him a kong or something other than your arm is a great plan.

Hissing at him when he bites.

A firm "no" and pick him up and redirect him

Reward and praise him when he takes the kong or toy.

People like to say that cats can't learn commands, but I disagree.

Use the "little" voice to praise, etc. Use the cross mom voice to tell him off. I bet Beth Bach, who is a long-time cat rescuer, has some good advice.