Protestants have the book of Malachi as the final book in their Old Testament so this is a book clearly held as Sacred Scripture by both Catholics and Protestants.
Catholics often refer to the Mass as the "Holy Sacrifice of the Mass" which is a term that Protestants would reject.
Now, there is a curious passage in the book of Malachi that may be a prophecy:
For from the rising of the sun to its setting my name is great among the nations, and in every place incense is offered to my name, and a pure offering; for my name is great among the nations, says the Lord of hosts.
Today, what is the pure offering in every place offered to the great name of the Lord?
Now, a Protestant will say, surely that is a late invention of the Catholic Church to understand this Old Testament verse that way. Maybe from the middle ages or something. Right?
OR maybe the first century?
The first quote of Malachi 1:11 in reference to the Sunday Eucharist is from the FIRST CENTURY (or the early second at the latest).
Gather together each Sunday,a break bread and give thanks, first confessing your sins, that your sacrifice
may be pure. And let no man, having a disagreement with his brother, join you until they have been reconciled, that your sacrifice may not be defiled. For it was this sacrifice that was spoken of by the Lord: “In every place
and at every time offer me a pure sacrifice; for I am a great king, says the Lord, and my name is wonderful
among the nations.”
St. Ignatius of Antioch, 107 AD:
Make certain, therefore, that you all observe one common Eucharist; for there is but one body of our Lord Jesus Christ, and but one cup of union with his blood, and one single altar of sacrifice —even as there is also but one bishop, with his clergy and my own fellow servitors, the deacons. This will ensure that all your doings are in full accord with the will of God (Letter to the Philadelphians 4)
St. Justin Martyr, 155 AD: ANOTHER reference to Malachi as a prophecy of the Mass:
God speaks by the mouth of Malachi, one of the twelve [minor prophets], as I said before, about the sacrifices at that time presented by you: “I have no pleasure in you, says the Lord, and I will not accept your sacrifices at your hands; for from the rising of the sun to the going down of the same, my name has been glorified among the Gentiles, and in every place incense is offered to my name, and a pure offering, for my name is great among the Gentiles” [Mal. 1:10-11]. He then speaks of those Gentiles, namely us [Christians] who in every place offer sacrifices to him, that is, the bread of the Eucharist and also the cup of the Eucharist (Dialogue with Trypho 41)
St. Irenaeus, 180AD: ANOTHER reference to Malachi as a prophecy of the Mass:
He took from among creation that which is bread, and gave thanks, saying, “This is my body.” The cup likewise, which is from among the creation to which we belong, he confessed to be his blood. He taught the new sacrifice of the new covenant, of which Malachi, one of the twelve [minor] prophets, had signified beforehand: “You do not do my will, says the Lord Almighty, and I will not accept a sacrifice at your hands. For from the rising of the sun to its setting my name is glorified among the Gentiles, and in every place incense is offered to my name, and a pure sacrifice; for great is my name among the Gentiles, says the Lord” [Mal. 1:10-11]. By these words he makes it plain that the former people will cease to make offerings to God but that in every place sacrifice will be offered to him, and indeed, a pure one, for his name is glorified among the Gentiles (Against Heresies 4:17:5)
St. Cyril of Jerusalem, 350 AD:
Then, having sanctified ourselves by these spiritual hymns, we beseech the merciful God to send forth his Holy Spirit upon the gifts lying before him, that he may make the bread the body of Christ and the wine the blood of Christ, for whatsoever the Holy Spirit has touched is surely sanctified and changed. Then, upon the completion of the spiritual sacrifice, the bloodless worship, over that propitiatory victim we call upon God for the common peace of the churches, for the welfare of the world, for kings, for soldiers and allies, for the sick, for the afflicted; and in summary, we all pray and offer this sacrifice for all who are in need (Catechetical Lectures 23:7-8)
That's right, THREE early Church sources PRIOR to 200AD clearly interpret Malachi 1:11 as referring the the Holy Sacrifice of the Mass. Think about that, that is well before the Canon of Scripture or the doctrine of the Trinity were settled!
For plenty more evidence that the Early Church taught Transubstantiation...