MARY, OUR MOTHER

SCRIPTURE COMMENTARY #489

And taking bread, he gave thanks and brake and gave to them, saying: "This is my body, which is given for you. Do this for a commemoration of me." In like manner, the chalice also, after he had supped, saying: "This is the chalice, the new testament in my blood, which shall be shed for you." (Luke 22:19-20)

IN THE HOLY MASS a little water is mixed with the wine. This is done, because the wine changed by our Lord at the Last Supper was mixed with water, this mixture being strictly prescribed for the wine used at the Paschal feast. The mixture of water with the wine at Mass has also a symbolic meaning, and is intended to remind us that in Jesus Christ there are two natures in One Divine Person.

[From 'A Practical Commentary on Holy Scripture' by Bishop Knecht, D.D.]
(1899 Douay-Rheims Bible)