Mark 14:26

(ubi sup.) That hymn in the Gospel of John (John 17.) may also be meant, which the Lord sang, returning thanks to the Father, in which also He prayed, raising His eyes to heaven, for Himself and His disciples, and those who were to believe, through their word. (ubi sup.) Beautifully also does the Lord lead out His disciples, when they had tasted His Sacraments, into the mount of Olives, to show typically that we ought through the reception of the Sacraments to rise up to higher gifts of virtue, and graces of the Holy Ghost, that we may be anointed in heart.

As they returned thanks, before they drank, so they return thanks after drinking; wherefore it is said, And when they had sung a hymn, they went out into the mount of Olives, to teach us to return thanks both before and after our food. He also shows by this that He was glad to die for us, because when about to be betrayed, He deigned to praise God. He also teaches us when we fall into troubles for the sake of the salvation of many, not to be sad, but to give thanks to God, who through our distress works the salvation of many. Again, He went out into a mountain, that they might come to Him in a lonely place, and take Him without tumult. For if they had come to Him, whilst He was abiding in the city, the multitude of the people would have been in an uproar, and then His enemies, who took occasion against Him, should seem to have slain Him justly, because He stirred up the people.

For by a hymn he means the praise of the Lord, as is said in the Psalms, The poor shall eat and be satisfied; they that seek after the Lord shall praise him. (Ps. 22:26, 29) And again, All such as be fat upon earth have eaten and worshipped. Jesus also is held captive on the mount of Olives, whence He ascended to heaven, that we may know, that we ascend into heaven from that place in which we watch and pray; there we are bound and do not tend back again to earth.