A.T. Robertson Commentary Mark 14:37

"And he cometh, and findeth them sleeping, and saith unto Peter, Simon, sleepest thou? couldest thou not watch one hour?" — Mark 14:37 (ASV)

Simon, sleepest thou? (Σιμων, καθευδεισ; ). The old name, not the new name, Peter. Already his boasted loyalty was failing in the hour of crisis. Jesus fully knows the weakness of human flesh .