There appeared an angel - from heaven - It was as necessary that the fullest evidence should be given, not only of our Lord's Divinity, but also of his humanity: his miracles sufficiently attested the former; his hunger, weariness, and agony in the garden, as well as his death and burial, were proofs of the latter. As man, he needs the assistance of an angel to support his body, worn down by fatigue and suffering. See at the end of Luke 22:44 (note).

an.

Luke 4:10,11 For it is written, He shall give his angels charge over you, to keep you...

Psalm 91:11,12 For he shall give his angels charge over you, to keep you in all your ways...

Matthew 4:6,11 And said to him, If you be the Son of God, cast yourself down: for it is written, He shall give his angels charge concerning you...

Matthew 26:53 Think you that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels?

1 Timothy 3:16 And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels...

Hebrews 1:6,14 And again, when he brings in the first-begotten into the world, he said, And let all the angels of God worship him...

strengthening.

Luke 22:32 But I have prayed for you, that your faith fail not: and when you are converted, strengthen your brothers.

Deuteronomy 3:28 But charge Joshua, and encourage him, and strengthen him: for he shall go over before this people...

Job 4:3,4 Behold, you have instructed many, and you have strengthened the weak hands...

Daniel 10:16-19 And, behold, one like the similitude of the sons of men touched my lips: then I opened my mouth, and spoke...

Daniel 11:1 Also I in the first year of Darius the Mede, even I, stood to confirm and to strengthen him.

Acts 18:23 And after he had spent some time there, he departed, and went over all the country of Galatia and Phrygia in order...

Hebrews 2:17 Why in all things it behooved him to be made like to his brothers...

The Cross the victory and Defeat of Darkness
'This is your hour, and the power of darkness.' --Luke xxii. 53. The darkness was the right time for so dark a deed. The surface meaning of these pathetic and far-reaching words of our Lord's in the garden to His captors is to point the correspondence between the season and the act. As He has just said, 'He had been daily with them in the Temple,' but in the blaze of the noontide they laid no hands upon Him. They found a congenial hour in the midnight. But the words go a great deal deeper than allusive …
Alexander Maclaren—Expositions Of Holy Scripture

The Duty of Constant Communion J. W.
"Do this in remembrance of me." Luke 22:19. It is no wonder that men who have no fear of God should never think of doing this. But it is strange that it should be neglected by any that do fear God, and desire to save their souls; And yet nothing is more common. One reason why many neglect it is, they are so much afraid of "eating and drinking unworthily," that they never think how much greater the danger is when they do not eat or drink it at all. That I may do what I can to bring these well-meaning …
John Wesley—Sermons on Several Occasions

Gethsemane
"And all the unknown joys he gives, Were bought with agonies unknown." Since it would not be possible for any believer, however experienced, to know for himself all that our Lord endured in the place of the olivepress, when he was crushed beneath the upper and the nether mill-stone of mental suffering and hellish malice, it is clearly far beyond the preacher's capacity to set it forth to you. Jesus himself must give you access to the wonders of Gethsemane: as for me, I can but invite you to enter …
Charles Haddon Spurgeon—Spurgeon's Sermons Volume 9: 1863