[168] Now at that time the group-of-six bhikkhus (chabbaggiyā bhikkhū), without having been invited, spoke the Dhamma in the midst of the Saṅgha. They reported this matter to the Blessed One. "Bhikkhus, the Dhamma should not be spoken in the midst of the Saṅgha by one who has not been invited (anajjhiṭṭha); whoever should speak it commits an offence of wrong-doing (dukkaṭa). Bhikkhus, I allow the elder (thera) bhikkhu either to speak the Dhamma himself or to invite another to speak it."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.