[LunaTheHamster1]

I think he is trying to work out what your hand is. When I am first getting to know my hamsters, If I see them looking as if they are going to bite, I move my hand out the way - nothing startling, just move it. Then they soon work out that you aren't to be bitten.
I think like Cypher suggested if you could get into a bath or big box, or a safe area with your hamster, and they get used to roaming around and over you this can help with the whole taming/bonding process. If need be you can use a mug or a box or something similar to transfer him from the cage to the 'safe area' until he gets used to you.