"Speak slowly, Michael. He is an honourable man"

This quote by Arthur Cohn is likely referring to a scenario in which Michael is speaking with someone else, and Arthur is warning him to be mindful with his words. Arthur is stressing the significance of speaking gradually and thoughtfully, as the person Michael is speaking to is an honourable guy. This suggests that the individual is someone of high ethical character and integrity, and therefore is worthy of to be treated with respect. Arthur is likely suggesting that Michael must be mindful of his words and take his time when speaking, regarding not offend or disrespect the honourable guy. This quote is a suggestion to be mindful of our words and to think before we speak, specifically when speaking with somebody of high ethical character. It is also a pointer to treat everybody with respect, no matter their status or position.