Ver. 5-8. Both Luke and John mention two angels in the habit of young men. Matthew speaks of one sitting upon the stone. They might see him sitting upon the stone, and yet find him within also, the motions of angels are quick and undiscernible to our sense, or the stone might be rolled inward. That they were affrighted is no wonder, considering how apt we are to be frightened by any apparitions. Concerning what the angel said to these women, See Poole on "Matthew 28:5", and following verses to Matthew 28:8. They presently flee from the sepulchre amazed, saying nothing to any till they came into the city, where they tell it to the disciples.
Related Commentaries of Mark 16:5
Mark 16:5
5 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.