It is perfectly understood by both parties that nothing of the kind is meant.

The invitation is given and accepted from quite different motives.

The merchant has the satisfaction of seeing at his table men of high official rank, and feels that the consideration which he enjoys among people of his own class is thereby augmented.

If he succeeds in obtaining the presence of three generals, he obtains a victory over a rival who cannot obtain more than two.

The general, on his side, gets a first-rate dinner, a la russe, and acquires an undefined right to request subscriptions for public objects or benevolent institutions.
Of course this undefined right is commonly nothing more than a mere tacit understanding, but in certain cases the subject is expressly mentioned.