John Gill Commentary Mark 14:47

"But a certain one of them that stood by drew his sword, and smote the servant of the high priest, and struck off his ear." — Mark 14:47 (ASV)

And one of them that stood by
One of the disciples that stood by Jesus, as Judas was betraying him, and the soldiers were laying hold on him, Peter by name:

drew a sword, and struck a servant of the high priest, and cut off
his ear ;
his right ear; the servant's name was Malchus; (See Gill on Matthew 26:51).