He who is wholly free of defilements, well-established in morality, endowed with self-control and truthfulness — he indeed is worthy of the yellow robe.

Verses nine and ten form a definitional pair: who is and is not worthy of the robe. Note that the criteria are interior. Defilement, morality, self-control, truthfulness — none of these are visible from the outside. The Buddha is locating the robe-worthiness not in the institution but in the interior architecture of the wearer. The teaching gives the institution its meaning back: the robe is worthy not because tradition says so, but because the person inside it has done the interior work the tradition was built around.