"Some days later [in the Spring of 1288] RABBAN SAWMA [emissary of Patriarch Yahballaha III of the Church of the East] said to MAR PAPA [Pope Nicholas IV], 'I wish to celebrate the Eucharist so that ye might see our use'; and the Pope commanded him to do as he had asked.
And on that day a very large number of people were gathered together in order to see how the ambassador of the Mongols celebrated the Eucharist. And when they had seen they had rejoiced and said, 'The language is different, but the use is the same.'
Now the day on which he celebrated was the Sunday [on which the prayer beginning] 'ainaw asya' [i.e. 'Who is the physician'] is recited. And having performed the mysteries, he went to MAR PAPA and saluted him. And the Pope said unto RABBAN SAWMA,
When the Council of Trent in its Decree on Sacred Books and Apostolic Traditions affirmed the "longer canon" of 73 books, it did so as a form of upholding the "stare decisis" of the Council of Florence a century before.
There was an attempt in the General Congregations...
...to make some kind of dogmatic pronouncement or clarification on the exact nature and relative authority of the books within the canon - protocanon, deuterocanon/apocrypha, etc.
But Agostino Card. Bonucci OSM successfully cut short this attempt by saying that the Council...
...should not attempt to resolve a matter that was a "disagreement between Augustine [who favored the longer canon] and Jerome [who favored the shorter]."
So, the decree's ultimate aim was defensive in nature, against the Protestant push to resolve definitively in Jerome's favor