Just having a bit of a look at the Patimokkha, and following some recent discussion with @josephzizys , I wanted to take a closer look at this rule and Vibhanga.
Let’s start with the Vibhanga.
padaṁ, anupadaṁ, anvakkharaṁ, anubyañjanaṁ.
The Vibhanga describes them as four methods of teaching. In two of those cases, the meaning is obvious.
The next syllable:
“rūpaṁ aniccan”ti vuccamāno, “run”ti opāteti.
when ‘rūpaṁ aniccaṁ’ is being said, he prompts him, saying, ‘rū’.
I’m not sure why @brahmali translates Anvakkharaṁ as “syllable by syllable”: would not “the next syllable” be better?
The next phrase:
“rūpaṁ aniccan”ti vuccamāno, “vedanā aniccā”ti saddaṁ nicchāreti.
when ‘rūpaṁ aniccaṁ,’ is being said, the other says, ‘vedanā aniccā.’
So far so clear.
The first two items (padaṁ, anupadaṁ) are less clear, because pada can mean “sentence” or “word”. Here, however, the commentary says it means “a line of verse”, which is implied in Brahmali’s translation “line”. This is interesting, because it means that the primary example of memorizing given is verse, a detail that clearly harks back to the Vedic tradition of teaching the memorizing of verses, for which the Pali uses the same verb vāceti. (Eg. dn4:20.7: Ahamassa mante vācetā.)
Assuming the commentary is correct, what are the two methods? It seems reasonable that the prefix anu- should have the same sense all three times it appears, namely “the next” or “following”. Thus anupada would be when the teacher recites asevanā ca bālānaṁ and the student joins in with paṇḍitānañca sevanā. Pada is where they start and finish together.
Turning to the non-offense clauses:
if they are made to recite together
Brahmali has “if they recite together”, which appears to be a mistake: it’s a causative form, and the commentary explains it as a case where a teacher gets an ordained and unordained student to recite together. But I don’t know why it has uddisāpeti?
ekato sajjhāyaṁ karonto
If they rehearse together
This refers to when they both know the text and recite it together. Thus it would seem that the main way layfolk would learn is by attending group recitations by the Sangha and chanting along, which is still how it is done today.
It’s worth noting that nowhere in the Vibhanga does it say anything about “memorizing” the teachings. Obviously that is the purpose of the methods, but the offence falls regardless of whether or not anything is actually memorized, and regardless of whether or not there is any intent to have them memorize.
The main question raised by this rule is, why is this a problem? The Buddha encouraged lay folk to learn discourses. Various reasons were proposed by Thanissaro in his BMC, but I don’t find any of them particularly convincing.
The background story says that when the group of six monks were teaching layfolk to memorize by reciting together, the the layfolk became rude and disrespectful to the monks.
But why would they? Surely one would develop respect for a teacher who is helping you? Indeed, at pli-tv-kd5:4.2.6 it is said,
Even the householders who wear white are respectful and deferential toward their teachers for teaching them the profession by which they make a living.
Perhaps, if we read into the origin story, the problem is the monks involved. The group of six monks were notorious bad boys, and it would be no wonder if lay folk were to lose respect for them when associating closely. Thus the rule, with its exceptions, is intended to curb forms of teaching that involve a close intimacy with layfolk, in favor of more public group recitation.
This would agree with the Vedic background, where such forms of teaching were only carried out in a close relation between student and teacher. Such a relation is similar to that between ordained monastics, but not layfolk in general.
Perhaps, although I’m still not really convinced. It would have been easy to take another way to solve this problem, for example, by having the Sangha appoint competent teachers for the layfolk.
The group of six monks are more legend than fact; a convenient literary device to invoke whenever bad monks are needed. The rule itself says nothing about them. Origin stories are not hugely reliable, especially in such instances where it would seem that Vedic cultural ideas were influential in one way or another.
I can’t shake the feeling that the true purpose for this rule was lost early on and we are just inventing post-facto justifications.