Albert Barnes on Matthew 28:6

He is risen, as he said. He had often predicted that he would rise, but the disciples did not understand it, and consequently did not expect it, Mt 16:21, 20:19.

The place where the Lord lay. The place where a body was deposited in a sepulchre was commonly a niche cut in the wall of the sepulchre. The sepulchre was usually large; that of David was more than a hundred feet in length, cut out of solid rock under ground, and separated into various apartments. All round the sides of those apartments were niches for the dead; or they were ranged around the sides, in places cut in the solid rock just large enough to contain the body. In such a place our Lord lay.

(h) "he said" Mt 27:63