Luke
Acts 20:36ESV·traditional attribution

And when he had said these things, he knelt down and prayed with them all.

John Calvin Reformed @genevareformer

36. And kneeling down. The inward affection is indeed the chiefest thing in prayer; yet the external signs, as kneeling, uncovering of the head, lifting up of the hands, have a double use; the first is, that we exercise all our members to the glory and worship of God; secondly, that by this exercise our sluggishness may be awakened, as it were.

Matthew Henry Presbyterian @wholebiblehenry

After the parting sermon that Paul preached to the elders of Ephesus, which was very affecting, we have here the parting prayer and tears, which were yet more affecting; we can scarcely read the account here given of them, and meditate upon them with dry eyes. I. They parted with prayer (Act 20:36): And, when he had thus spoken, he kneeled down, and prayed with them all.

Commenting on Acts 20:36-38

Albert Barnes Presbyterian @notesbybarnes

Verse 36. He kneeled down. The usual attitude of prayer. It is the proper posture of a suppliant. It indicates reverence and humility; and is represented in the Scriptures as the common attitude of devotion, ; . (a) "kneeled down" .