[789] Now at that time there was a festival in Sāvatthī. People, having invited bhikkhus, fed them. That family too invited bhikkhus. The bhikkhus, being scrupulous, did not accept, [thinking]: "It has been prohibited by the Blessed One to chew or eat hard food or soft food in families designated as trainees (sekkhasammata), having received it with one's own hand." Those people complained, criticized, and spread it about, saying: "What indeed is the use of our living, since the venerable ones do not accept from us?" Bhikkhus heard those people complaining, criticizing, and spreading it about. Then those bhikkhus reported this matter to the Blessed One. Then the Blessed One, on account of that incident and in that connection, having given a talk on the Dhamma, addressed the bhikkhus: "Bhikkhus, I allow one who has been invited to chew or eat hard food or soft food in families designated as trainees, having received it with his own hand. And thus, bhikkhus, you should recite this training rule (sikkhāpada):
"Whatever families have been designated as trainees, should any bhikkhu, without being previously invited, chew or eat hard food or soft food in such families designated as trainees, having received it with his own hand, it is to be confessed by that bhikkhu: 'Friend, I have committed a blameworthy act, unsuitable, which is to be confessed (pāṭidesanīya); I confess it.'"
And thus this training rule was laid down by the Blessed One for the bhikkhus.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.