35 All this shows plainly enough that St. Cyril was in perfect accord with this Apostolic See and that Our Predecessors regarded his measures as their own, and gave them their complete approval. Thus St. Celestine, after other numerous proofs of his confidence in St. Cyril and his gratitude towards him, writes as follows: We rejoice in the vigilance shown by Your Holiness, wherein you surpass even the example set by your predecessors, themselves always defenders of the orthodox faith. . . . You have laid bare all the wiles of crafty teachers. . . . This is indeed a great triumph that you have won for our faith, in asserting our truth so valiantly and thus overcoming opposition to it by the testimony of Holy Writ.
Source: Orientalis Ecclesiae (Vatican.va)