Hold a dictionary and say other people's English

[Xinfu]

-You can't hold a dictionary in/on your hand and say other people's English is wrong.

Which preposition should I use? Is there any difference in meaning?

Is my sentence natural and good English?

[Rusty]

hold something in one's hand
This is the meaning you intended in your natural and good English.

hold something on one's hand
This is used when describing that something is on top of, attached to or wound around someone's hand and pressure is being applied to keep it there. If a band-aid wouldn't stay on because it got a bit wet, for example, we could hold it on our hand with one of our fingers until we could secure a replacement. We would hold it in our hand if it came completely off and we were about to throw it away.

[Xinfu]

Thank you~