the splitting of the moon,
The meaning of this verse is hotly disputed between Muslim scholars.
The conservative scholars hold that Muhammad performed the miracle of
splitting the moon as a sign of his prophethood. Many modern or more
liberal Muslims either see it in some sense metaphorical or as a
future event that will happen as a sign for the end of the world.
See also these comments.
Statements by various Muslims:
Others even try to read it as a scientific prophecy that has been fulfilled
in the landing on the moon, see this discussion.