Therein, the Middle Length Rehearsal according (to the division) into Fifties consists of a triad of compilations of fifty (discusses each) named Mūla, 'the Initial', Majjhima, 'the Middle' and Upari, 'the Final';

according to chapters (vagga), A vagga is to be taken as a group of 10, for generally, the term is applicable to a dasaka -- Ṭ it is a combination Samāyoga, 'compound' (saṃyoga) or a 'collection' (samudāya) -- Ṭ. of fifteen chapters assigning five chapters each to each one of the fifties;

according to the (number of) discourses, The terms sutta and suttanta are identical in meaning. it contains one and a half hundred and two discourses;

according to the (number of) words, Pada, 'term' or morphological hint, but Ṭ takes it as an 8-syllable metrical line when the text is recited or chanted in 8-syllable units as is usually done in formal recitation (e.g. paritta ceremony). The number of such padas is said to be 80,523. It further adds that since there are metrical lines ranging from 9 to 12 syllables when a bhāṇavāra, 'session at recital' consists of 2,500 of such stanzas, the number of bhāṇavāras and syllables is reconciled by specifying here the number of syllables. Hence the statement 80,523 pada = 740,053 akkhara in the Majjhimanikāya. 80,000 words exceeded by 523 words.

Hence, have the Ancients said:

It is said: 80,000 words and 500 more

and twenty-three again -- so has the (number of) words been specified.

According to syllables, Akkhara, characters in a writing system, letters as oppposed to sadda (articulation), but here it evidently refers to what grammarians call vaṇṇa, syllables with specific metrical values of one or two syllabic instances (Sk. mātrā). 700,000 syllables and 40,000 and fifty-three syllables.

According to sessions of recital, That extent of the text which can be recited at one sitting, explained in Ṭ as 250 gāthās of 32 syllables each i.e. 8,000 syllables. eight sessions and half a session exceeded by twenty-three words.

According to textual sequences Ṭ defines desanānusandhito: ekasmiṃ eva hi sutte purimapacchimānaṃ desanābhāgānaṃ sambandho anusandhānato anusandhi. Although they are given as 3, Ṭ makes it 4 by dividing the sequence of disposition into 2 as one's own and another's. The 3 are explained as: (1) dhammaṃ suṇantānaṃ pucchāvasena; (2) desentassa satthusāvakassa dhammapaṭiggāhakānañ ca ajjhāsayavasena; (3) desetabbassa dhammassa vasena. Examples are furnished for each of the 4 categories (Be p. 21f). -- in brief, there are three sequences: that associated with a question, with an intention and as a natural sequence

but in detail here are found 3,000 sequences and 900. This is the number in the whole of M -- Ṭ.

Hence have the Ancients said:

Three thousand sequences, likewise 900 more --

these are the methods of sequence declared to belong to the Middle Length collection.

3. Therein, among the Fifties, the initial Fifty is the first; among the chapters, the Mūlapariyāyavagga is the first; among the discourses, the Mūlapariyāyasutta is the first;

even of that, the introductory account (nidāna), beginning with: ‘Thus was it heard by me’ narrated by venerable Ānanda during the time of the First Great Recital is the beginning.

And this First Great Recital has been explained at the beginning of Sumaṅgalavilāsinī, the commentary to the Dīghanikāya.

Therefore, it should be known as explained there.