[8] Now at that time the Blessed One was walking up and down in the open air without sandals. Thinking, "The Teacher walks without sandals," the elder bhikkhus also walked without sandals. But the group-of-six bhikkhus, while the Teacher was walking without sandals and even the elder bhikkhus were walking without sandals, walked wearing sandals. Those bhikkhus who were of few wishes … complained, criticized, and spread it about, saying: "How indeed can the group-of-six bhikkhus, while the Teacher is walking without sandals and even the elder bhikkhus are walking without sandals, walk wearing sandals?" Then those bhikkhus reported this matter to the Blessed One.
"Is it true, as they say, bhikkhus, that the group-of-six bhikkhus, while the Teacher was walking without sandals and even the elder bhikkhus were walking without sandals, walked wearing sandals?"
"It is true, Blessed One."
The Buddha, the Blessed One, rebuked them: "How indeed, bhikkhus, can those foolish men (moghapurisa), while the Teacher is walking without sandals and even the elder bhikkhus are walking without sandals, walk wearing sandals? For even householders, bhikkhus, dressed in white, for the sake of a craft by which they earn their living, will dwell respectful, deferential, and living in conformity toward their teachers. Herein, bhikkhus, it would be becoming of you that, having gone forth in a Dhamma and Discipline so well proclaimed, you should dwell respectful, deferential, and living in conformity toward teachers and those of teacher's standing, toward preceptors (upajjhāya) and those of preceptor's standing. This, bhikkhus, does not conduce to the confidence of those without confidence …" Having rebuked them and given a talk on the Dhamma, he addressed the bhikkhus: "Bhikkhus, when teachers or those of teacher's standing, preceptors or those of preceptor's standing, are walking without sandals, one should not walk wearing sandals. Whoever should so walk commits an offense of wrong-doing (dukkaṭa). And, bhikkhus, sandals should not be worn within a monastery. Whoever should wear them commits an offense of wrong-doing."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.