According to the Qur’an (18:83-86), a man named Dhul-Qarnayn (whom commentators often identify as Alexander the Great or Cyrus the Great) reached the place where the sun sets, and he found it going down into a spring of muddy water. Modern Muslims, aware of the fact that this is impossible, try to reinterpret the passage to mean that the sun, through some sort of optical illusion, merely seemed to Dhul-Qarnayn to be setting in a pool. Unfortunately for Muslims who want to reinterpret the Qur’an, however, Muhammad himself said that the sun sets in a pool of water (Sunan Abu Dawud 3991). So unless our Muslim friends want to tell us that they understand the Qur’an better than their prophet, we have no choice but to assume that Allah meant what he said about the sun setting in a murky spring.
The Son of God 