John 13:18

οὐ περὶ πάντων. There is one who knows, and does not do, and is the very reverse of blessed. I know the character of the Twelve whom I chose (John 6:70; John 15:16); the treachery of one is no surprise to Me. For the elliptical ἀλλ' ἵνα, ‘but this was done in order that,’ so frequent in S. John, see on John 1:8. Here we may supply ἐλεξάμην: but I chose them in order that. Winer, p. 398.

ἡ γραφὴ πλ. see on John 2:22 and John 12:38. The quotation is taken, but with freedom, from the Hebrew of Psalms 41:9 : for ἐπῆρεν ἐπ' ἐμὲ τ. πτέρναν αὐτοῦ both Hebrew and LXX. have ‘magnified his heel against me,’ ἐμεγάλυνεν ἐπ' ἐμὲ πτερνισμόν. The metaphor here is of one lifting up his foot before kicking, but the blow is not yet given. This was the attitude of Judas at this moment. Jesus omits ‘Mine own familiar friend whom I trusted.’ He had not trusted Judas, and had not been deceived as the Psalmist had been: ‘He knew what was in man’ (John 2:25). The variations from the LXX. are still more remarkable in the first clause. S. John quotes ὁ τρώγων μετ' ἐμοῦ τὸν ἄρτον, the LXX. having ὁ ἐσθίων ἄρτους μου. We notice (1) τρώγειν, the verb used of eating Christ’s Flesh and the Bread from Heaven (John 6:54; John 6:56-58), and nowhere else in N.T. excepting Matthew 24:38, instead of the much more common ἐσθίειν: (2) τὸν ἅρτον, the bread, instead of ἄρτους, bread or loaves: (3) μετ' ἐμοῦ for μου, if the reading μετ' ἐμοῦ be genuine, which is doubtful. To eat bread with a man is more than to eat his bread, which a servant might do. The variations can scarcely be accidental, and seem to point to the fact that the treachery of Judas in violating the bond of hospitality, so universally held sacred in the East, was aggravated by his having partaken of the Eucharist. That Judas did partake of the Eucharist seems to follow from Luke 22:19-21, but the point is one about which there is much controversy.

S. John omits the institution of the Eucharist for the same reason that he omits so much,—because it was so well known to every instructed Christian; and for such he writes.