Matthew 28:2

A great earthquake - Σεισμος, a shaking or commotion of any kind: probably the word means no more than the confusion caused among the guards by the angel's appearance. All this had taken place before the women reached the sepulchre.

The angel of the Lord descended from heaven - Matthew is very particular in this, to show that the word angel is not to be taken in the sense of an ordinary messenger, who might have come from Joseph of Arimathea, or from any other; but in the sense of an extraordinary messenger, who descended from God, out of heaven, for this very purpose. It is likely that the angel had descended, rolled away the stone, and was sitting on it, before the women reached the tomb.

There was a great earthquake - Rather there "had been." It does not mean that this was while they were there, or while they were going, but that there "had been" so violent a commotion as to remove the stone. The word rendered here as "earthquake" does not of necessity mean that the convulsion extended to the earth, but only that there had been such a concussion as to remove the stone.

And sat upon it - Sat upon it when the keepers saw him, Matthew 28:4. It is not said that he was sitting when he appeared to the women. From Luke it would rather appear that he was standing.

28:2 An angel of the Lord had rolled away the stone and sat upon it - St. Luke and St. John speak of two angels that appeared: but it seems as if only one of them had appeared sitting on the stone without the sepulchre, and then going into it, was seen with another angel, sitting, one where the head, the other where the feet of the body had lain.