III. He sends quotations from the Fathers, and announces that the churches of the East have accepted the Tome.
And in order that you may be the fuller instructed in all things, beloved, I have sent you certain quotations from our holy Fathers, that you may clearly gather what they felt and what they preached to the churches about the mystery of the Lord's Incarnation, which quotations our deputies produced at Constantinople also together with our epistle. And you must understand that the whole church of Constantinople, with all the monasteries and many bishops, have given their assent to it, and by their subscription have anathematized Nestorius and Eutyches with their dogmas. You must also understand that I have recently received the bishop of Constantinople's letter, which states that the bishop of Antioch has sent instructions to all the bishops throughout his provinces, and gained their assent to my epistle, and their condemnation of Nestorius and Eutyches in like manner.
Source: Letters (New Advent)