At last, after five days, having observed up to that point the sacraments of the old Passover, he brought them to perfection, and handed over the new sacraments to his disciples to be observed from that time forward. Then, having gone out to the Mount of Olives, he was seized by the Jews and crucified the next morning. He redeemed us from the sway of the devil on that very day when the ancient people of the Hebrews remembered casting aside the yoke of slavery under the Egyptians by the immolation of a lamb.
Why did he choose [Judas], and … make him steward? To show his perfect love and his mercy. [It was] also that our Lord might teach his church that, even if there are false teachers in it, it is nevertheless the true seat [of authority]. For the seat of Judas did not come to naught with the traitor himself. It was also [to teach] that, even if there are evil stewards, the stewardship itself is true. He therefore washed his feet, [those very feet] by means of which he had arisen and gone to [Jesus’] slayers. Jesus kissed the mouth of him who, by means of it, gave the signal for death to those who apprehended him. He reached out and gave bread into that hand that reached out and took his price, and sold him unto slaughter. Commentary on Tatian’s Diatesseron.