Upvote:2
I hope that this was written to indicate that Jesus had, in his burial, fulfilled the prophecy of Isaiah at 53:9 (RSVCE)
" And they made his grave with the wicked and with a rich man in his death..."
Clearly, only a rich man could afford to construct a grave hewn in rock. And, Matthew 27:57 in deed depicts Joseph of Arimathe'a as a rich man !