Considering John's relations with David Harum, it was natural that he should wish to think as well of him as possible, and he had not (or thought he had not) allowed his mind to be influenced by the disparaging remarks and insinuations which had been made to him, or in his presence, concerning his employer.

He had made up his mind to form his opinion upon his own experience with the man, and so far it had not only been pleasant but favorable, and far from justifying the half-jeering, half-malicious talk that had come to his ears.

It had been made manifest to him, it was true, that David was capable of a sharp bargain in certain lines, but it seemed to him that it was more for the pleasure of matching his wits against another's than for any gain involved.

Mr.
Harum was an experienced and expert horseman, who delighted above all things in dealing in and trading horses, and John soon discovered that, in that community at least, to get the best of a "hoss-trade" by almost any means was considered a venial sin, if a sin at all, and the standards of ordinary business probity were not expected to govern those transactions.
David had said to him once when he suspected that John's ideas might have sustained something of a shock, "A hoss-trade ain't like anythin' else.

A feller may be straighter 'n a string in ev'rythin' else, an' never tell the truth--that is, the hull truth--about a hoss.