According to Joseph A. Jungmann, S.J. in The Mass of the Roman Rite, the mixture of water with the wine was expressly mentioned as early as the second century. Jungmann offers three explanations for this mixture: “intimate union of the faithful with Him to whom they have bound themselves in faith”; “reference to the blood and water which flowed from Christ’s side on Calvary”; and in the Orient “the wine and water were made to represent the divine and human natures in Christ”.
