From the Saddhammasaṅgaha:
"The Venerable Thera Mahākassapa, who was the senior of the Order of many thousand bhikkhus, assembled the order of bhikkhus there. Then the Venerable Thera Mahākassapa addressed the bhikkhus: “Friends, the whole of the Aṭṭhavaṇṇanā, compiled by the ancients for the purpose of explaining the hidden meaning of the Aṭṭhakathā of the three Piṭakas, does not serve the purpose of bhikkhus residing in different countries. Some are written in many terse expressions according to the grammar of the Sinhalese language, some are written in the dialect of Māgadha, which is the basic language, but they have been confused and twisted by translation. We should, removing the drawback in the translation, compile a complete and clear Aṭṭhavaṇṇanā.” The bhikkhus replied: “Reverend Sir, let the Thera get the king issue an order therefor.”
At that time the king with his following came out of the city and went to the Vihāra. Paying homage to the Order of bhikkhus headed by the Thera Mahākassapa, he took his seat on one side. Then the Thera said to him: “O great king, should the compilation of the Aṭṭhavaṇṇanā of the Aṭṭhakathās of the Piṭakas be thy duty.” “It is well, reverend sir, I will lend my bodily co-operation; let the Order of bhikkhus be confident.” Thereafter the king, paying homage to the Order of bhikkhus, entered the city.
Then the elder bhikkhus, having finished their meal, assembled in the mansion, built by King Parakkamabāhu, and beginning thus an Aṭṭhavaṇṇanā of the Sāmantapāsādikā, an Aṭṭhakathā on the Vinaya-Piṭaka, compiled…
Thus being requested by King Parakkamabāhu, the Thera Mahākassapa together with many thousand theras put forth their exertion and even as the rehearsal of the Dhamma and the Vinaya, completed the Aṭṭhavaṇṇanā of the Aṭṭhakathā on the Piṭakas. When the compilation of the Aṭṭhavaṇṇanā was completed, many wonders, including the earthquake and the like, were manifested, and the gods shouted applause. This compilation of the Aṭṭhavaṇṇanā of the Aṭṭhakathā on the Piṭakas was completed in one year.
To this effect said the Ancients:
7 “One thousand five hundred and eighty-seven years after the attainment of the Parinibbāna by the Sambuddha, Parakkama became king.
8 He, who was consecrated and fond of the lustre of the Sāsana, suppressed his enemies by the power of his great merit.
9 For this purpose Parakkamabāhu, king of Sīhala, made the Nikāyas harmonious and the Sāsana pure.
10 & 11 Being requested by King Parakkamabāhu who wished that the Sāsana might endure, the great Thera Kassapa, leader of the Order, exerted for the Sāsana so that the Sāsana might prosper in the island of Tambapaṇṇi.’
> 12 The explanation of hidden meaning of the Aṭṭhakathā on the Piṭakas does not serve altogether the purpose of bhikkhus everywhere.
> 13 Some are written in many terse expressions according to the Sinhalese grammar which by its nature is difficult to be understood.
> 14 Some, having made an attempt in the language of Māgadha, have written something intermixed with translation.
> 15 Here, in many places is found the worthlessness in composition; things are not clearly described and they are not intelligible without difficulty in meaning.
> 16 From what is thus incomplete, how can the inhabitants of different countries make out the meaning throughout?
> 17 From this, leaving aside the translation and taking the substance throughout, I shall make a clear and full exposition.’
> 18 & 19 The works called the Sāratthadīpanī, the Sāratthamañjūsā, and the Paramatthappakāsinī, were expounded by the great theras as Vaṇṇanā of the three Piṭakas and as explanation of their hidden meanings…"—Law, Bimala Churn, trans. A Manual of Buddhist Historical Traditions (Saddhamma-Sangaha) . Calcutta: University of Calcutta, 1941
It appears things were done differently in the Middle Ages after all.
R