It is a slight declension in the character of Cyrus to lay down this law, "equestrian once, equestrian always." Xenophon has to account for the actual Persian horror of pedestrianism: Cyrus himself can dismount, and so can the Persian nobles with Cyrus the Younger, but still the rule is "never be seen walking;" and without the concluding paragraph the dramatic narrative that precedes would seem a little bit unfinished and pointless: with the explanation it floats, and we forgive "the archic man" his partiality to equestrianism, as later on we have to forgive him his Median get-up and artificiality generally, which again is contrary to the Xenophontine and the ideal Spartan spirit.
C4.

Xenophon has this theory of mankind: some are fit to rule, the rest to be ruled.

It is parallel to the Hellenic slavery theory.

Some moderns, e.g.Carlyle (Ruskin perhaps) inherit it, and in lieu of Hellenic slavery we have a good many caste-distinction crotchets still left.
C4.13, fin.

The first salaam, ominous of the advent of imperialism; the sun's rim visible, and a ray shot up to the zenith.
C5.