The attitude of those who heard Christ's promise and His reaction furnish an argument for the Real Presence. It is very evident that they understood Our Lord to be referring to His own body and blood, and not to a mere symbol.

Now, from Christ's manner of acting on other occasions we can conclude that if they had interpreted Him wrongly He would have set them right. Thus, when the disciples understood literally His announcement: "Lazarus sleepeth," He told them plainly: "Lazarus is dead." Again, when He spoke of meat which He had to eat, and they thought He referred to material food, He told them: "My meat is to do the will of Him that sent Me" (John 11: 11-14; 4: 32-34). But on the present occasion, when it was evident that His followers were accepting His words literally, He did not say: "I intend merely to give you bread and wine as a symbol of My body and blood." On the contrary, He repeated His promise even more explicitly; and though He saw many departing from His company, He uttered not a single word implying that He had been speaking in figurative language.

The Seven Sacraments
Rev. Francis J. Connell, C.SS.R., S.T.D.