John 6:53,54

εἶπεν οὖν … ἡμέρᾳ. Instead of explaining the mode Jesus merely reiterates the statement. The reason of this is that their attention was thus more likely to be fixed on the necessity of using Him as the living bread. The difficulty of the statement disappears when it is perceived that the figure of speech is not to be found in the words “flesh” and “blood,” but in the words “eating” and “drinking”. The actual flesh and blood, the human life of Christ, was given for men; and men eat His flesh and drink His blood, when they use for their own advantage His sacrifice, when they assimilate to their own being all the virtue that was in Him, and that was manifested for their sakes. As Lücke points out, the σὰρξ καὶ αἷμα form together one conception and are equivalent to the με of John 6:57. If αἷμα stood alone it might refer especially to the death of Christ, but taken along with σάρξ it is more natural to refer the double expression to the whole manifestation of Christ; and the “eating and drinking” can only mean the complete acceptance of Him and union with Him as thus manifested. [τρώγω, originally the munching of herbivorous animals, was latterly applied to ordinary human eating.]