And entering into the sepulchre,
they saw a young man sitting on the right side,
clothed in a long white garment;
and they were affrighted.
Mark 16:5
Adam Clarke
Charles Spurgeon
Matthew Henry
They see an angel.
The angel appeared in the likeness of a man, of a young man for angels, though created in the beginning, grow not old, but are always the same perfection of beauty and strength and so shall glorified saints be, when they are as the angels. This angel was sitting on the right hand as they went into the sepulchre, clothed with a long white garment...The sight of him might justly have encouraged them, but they were affrighted. Thus many times that which should be matter of comfort to us, through our own mistakes and misapprehensions proves a terror to us.