Take a careful look at St. Luke chapter 11, and you'll find some pretty convincing reasons for believing that the Our Father was meant from the start to be the very prayer by which the elements on the altar are consecrated.
First, it is the only prayer Jesus specifically tells His disciples to say (hence, it is called the Lord's Prayer). Then, immediately following this prayer there comes the curious story Jesus tells of the friend at midnight:
"And he said unto them, Which of you shall have a friend, and shall go unto him at midnight, and say unto him, Friend, lend me three loaves; for a friend of mine in his journey is come to me, and I have nothing to set before him? And he from within shall answer and say, Trouble me not: the door is now shut, and my children are with me in bed; I cannot rise and give thee. I say unto you, Though he will not rise and give him, because he is his friend, yet because of his importunity he will rise and give him as many as he needeth."
Here we have three friends. The journeying friend, the friend to whom he comes, and the friend who is at home with his children at midnight. Why, we must ask, all this detail? Surely, if there were to be nothing more than a simple point of comparison (If ye then, being evil, know how to give good gifts unto your children: how much more shall your heavenly Father give the Holy Spirit to them that ask him?), then it could have been a much simpler story. Why three friends? Why midnight? Why three loaves? And--most significantly--why does this come immediately after the Lord's Prayer?
There is something latent here which is meant to be uncovered: it's all about Christ. It's all about the Holy Supper.
Midnight, because the midnight hour is when the voice is heard, "The Bridegroom cometh; go ye out to meet him." Midnight is when "I will rise to give thanks," as the Psalmist says. Midnight is when Christ comes.
Three loaves, because Jesus is the Triune God. He is Himself our daily bread. He is the Bread of Life.
Three friends: one is the journeying church, on the journey of life; she comes to the second, i.e., the pastor, who has nothing of his own to give; so he turns to the third, i.e., the Father, and says, "Our Father who art in heaven . . . give us daily bread, that is, lend me three loaves!"
And the Father gives as much as we need, as Jesus promises here: "Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you." This is about asking that Christ will be given to us; i.e., that the Holy Spirit will do His primary work of bringing Christ to us in the Supper; which is why Jesus says here, "how much more shall your heavenly Father give the Holy Spirit to them that ask him?"
In short, this entire section is about the Mass. If you don't see that, have another look.