Luke 6:19

But after that the High Priest had made publicly known His choice of Apostles, He did many and great miracles, that the Jews and Gentiles who had assembled might know that these were invested by Christ with the dignity of the Apostleship, and that He Himself was not as another man, but rather was God, as being the Incarnate Word. Hence it follows, And the whole multitude sought to touch him, for there went virtue out of him. For Christ did not receive virtue from others, but since he was by nature God, sending out His own virtue upon the sick, He healed them all.

You will scarcely find any where that the multitudes follow our Lord to the higher places, or that a sick person is healed on a mountain; but having quenched the fever of lust and lit the torch of knowledge, each man approaches by degrees to the height of the virtues. But the multitudes which were able to touch the Lord are healed by the virtue of that touch, as formerly the leper is cleansed when our Lord touched him. The touch of the Saviour then is the work of salvation, whom to touch is to believe on Him, to be touched is to be healed by His precious gifts.

But observe all things carefully, how He both ascends with His Apostles and descends to the multitude; for how could the multitude see Christ but in a lowly place. It follows him not to the lofty places, it ascends not the heights. Lastly, when He descends, He finds the sick, for in the high places there can be no sick.

(de Con. Ev. ii. 19.) Now this long discourse of our Lord, Luke begins in the same way as Matthew; for each says, Blessed are the poor. Then many things which follow in the narration of each are like, and finally the conclusion of the discourse is found to be altogether the same, I mean with respect to the men who build upon the rock and the sand. It might then easily be supposed that Luke has inserted the same discourse of our Lord, and yet has left out some sentences which Matthew has kept, and likewise put in others which Matthew has not; were it not that Matthew says the discourse was spoken by our Lord on the mountain, but Luke on the plain by our Lord standing. It is not however thought likely from this that these two discourses are separated by a long course of time, because both before and after both have related some things like, or the same. It may however have happened that our Lord was at first on a higher part of the mountain with His disciples alone, and that then he descended with them from the mount, that is, from the summit of the mountain to the flat place, that is, to some level ground, which was on the side of the mountain, and was able to hold large multitudes, and that there He stood until the crowds were gathered together to Him, and afterwards when He sat down His disciples came nearer, and to them, and the rest of the multitude who were present, He held the same discourse.