John Gill Commentary Mark 14:33

"And he taketh with him Peter and James and John, and began to be greatly amazed, and sore troubled." — Mark 14:33 (ASV)

And he takes with him Peter, and James, and John Who were witnesses of his transfiguration on the mount, and now of his sorrows in the garden:

and began to be sore amazed ; to be in great consternation and astonishment, at the sight of all the sins of his people coming upon him; at the black storm of wrath, that was gathering thick over him; at the sword of justice which was brandished against him; and at the curses of the righteous law, which, like so many thunderbolts of vengeance, were directed at him: no wonder it should be added,

and to be very heavy: both with sin and sorrow ; (See Gill on Matthew 26:37).