Albert Barnes Commentary Matthew 28:4

"and for fear of him the watchers did quake, and became as dead men." — Matthew 28:4 (ASV)

The keepers did shake. It was night. The appearance was sudden and unexpected, and to them terrifying. The stone was probably suddenly removed. At the noise, the light, and the suddenness of the appearance, they were terrified.

And became as dead men. Probably by terror they fainted, or were thrown into a swoon. At this time it is probable that the Lord Jesus arose; and for this reason He was not seen by them when He came forth. At what precise time of the night this was, we are not certainly informed. The narrative, however, leads us to suppose that it was not long before the women came to the sepulchre, or near the break of day.