A man, who is himself, we shall suppose, of a competent fortune, and of no profession, being introduced to a company of strangers, naturally treats them with different degrees of respect, as he is informed of their different fortunes and conditions; though it is impossible that he can so suddenly propose, and perhaps he would not accept of, any pecuniary advantage from them.
 David Hume, An Enquiry Concerning the Principles of Morals (1751). copy citation

Context

“But not to go so far as prisoners of war or the dead, to find instances of this disinterested regard for riches; we may only observe, with a little attention, those phenomena which occur in common life and conversation. A man, who is himself, we shall suppose, of a competent fortune, and of no profession, being introduced to a company of strangers, naturally treats them with different degrees of respect, as he is informed of their different fortunes and conditions; though it is impossible that he can so suddenly propose, and perhaps he would not accept of, any pecuniary advantage from them. A traveller is always admitted into company, and meets with civility, in proportion as his train and equipage speak him a man of great or moderate fortune. In short, the different ranks of men are, in a great measure, regulated by riches;” source