2 And when supper was done, (the devil having now put into the heart of Judas Iscariot, the son of Simon, to betray him,)
Augustine: A secret suggestion, not made to the ear, but to the mind. . . . Judas then had already conceived, through diabolical instigation, the intention of betraying his Master.
Chrysostom: The Evangelist inserts this as if in astonishment: our Lord being about to wash the feet of the very person who had resolved to betray Him. It shows the great wickedness too of the traitor, that even the partaking of the same table, which is a check to the worst of men, did not stop him.
3 Knowing that the Father had given him all things into his hands, and that he came from God, and goeth to God;
Augustine: The Evangelist being about to relate so great an instance of our Lord’s humility, reminds us first of His lofty nature.
Gregory: He had even His persecutors in His hand that He might convert them from malice to love of Him.
Origen: The Father hath given all things into His hands; i.e. into His power; for His hands hold all things [1 Chr 29:12]; or to Him, for His work; My Father worketh hitherto, and I work [John 5:17].
Chrysostom: What is given Him is the salvation of the believers. Think not of this giving up in a human way. It signifies His honor for, and agreement with, the Father. For as the Father has given up all things to Him, so has He given up all things to the Father [1 Cor 15:24].
Augustine: Knowing too, that He was come from God, and went to God; not that He left God when He came, or will leave us when He returns.
Scripture from the Douay-Rheims Bible. Commentary from St. Thomas Aquinas, Catena Aurea, Vol. IV (London: Rivington, 1845).