I did not say that. But it does not have the same authority as a Canon of the Council and, though authoritative, is not infallible unlike a Canon of the council, except where it reiterates doctrine affirmed in Canons of the Council or previous doctrine. It only has the mandate not the ultimate approbation of the Council [because it came after the end of the Council] - and so is not on par with its canons.
All I am saying is that there is more than enough proof that the words “Mystery of Faith” were given to the Apostles by Christ.
newadvent.org/summa/4078.htm
Summa Theologica St Thomas Aquinas
Article 3. Whether this is the proper form for the consecration of the wine: “This is the chalice of My blood,”
Objection 9. Further, the words whereby this sacrament is consecrated draw their efficacy from Christ’s institution. But no Evangelist narrates that Christ spoke all these words. Therefore this is not an appropriate form for the consecration of the wine.
On the contrary, The Church,
instructed by the apostles, uses this form. …that He Himself may be just, and the justifier of him who is of the faith of Jesus Christ": and on this account we add, “The Mystery of Faith.” Thirdly, for removing sins which are the impediments to both of these things, according to Hebrews 9:14: “The blood of Christ . . . shall cleanse our conscience from dead works,” that is, from sins; and on this account, we say, “which shall be shed for you and for many unto the forgiveness of sins.”
Reply to Objection 5. The word “mystery” is inserted, not in order to exclude reality, but to show that the reality is hidden, because Christ’s blood is in this sacrament in a hidden manner, and His Passion was dimly foreshadowed in the Old Testament.
Reply to Objection 6. It is called the “Sacrament of Faith,” as being an object of faith: because by faith alone do we hold the presence of Christ’s blood in this sacrament.
*Cum Marthae circa *( November 29, 1202) Pope Innocent III
(On the sacramental form of the Eucharist)
You have asked who has added to the words of the formula used by Christ himself when he transubstantiated the bread and wine into his body and blood, the words which are found in the Canon of the Mass generally used by the Church, but which none of the evangelists has recorded… Namely, in the Canon of the Mass, we find the words “Mystery of faith” inserted into the words of Christ… Surely there are many words and deeds of the Lord which have been omitted in the gospels; of these we read that the apostles have supplemented them by their words and expressed them in their actions… But, in the words which are the object of our inquiry, Brother, namely the words “Mystery of faith”, some have thought to find support for their error; they say that in the sacrament of the altar it is not the reality of the body and blood of Christ which is [there] but only an image, an appearance, a symbol, since Scripture sometimes mentions that what is received at the altar is sacrament, mystery, figure. These people fall into such error because they neither understand correctly the testimony of the Scriptures nor receive respectfully the divine sacraments, ignorant of both the Scriptures and the power of God [cf. Mt 22:29]… Yet, the expression “Mystery of faith” is used, because here what is believed differs from what is seen, and what is seen differs from what is believed. For what is seen is the appearance of bread and wine and what is believed is the reality of the flesh and blood of Christ and the power of unity and love…Therefore, … we believe that the apostles have received from Christ the words of the formula found in the Canon, and their successors have received them from the apostles…