Sahih Muslim, Chapter: Faith (Kitab Al Iman)

The Messenger of Allah (may peace and blessings be upon him) led the morning prayer at Hudaybiya. There were some marks of the rainfall during the night. At the conclusion of prayer he turned towards people and observed: Do you know what your Lord has said? They replied: Allah and His Messenger know best. Upon this he (the Holy Prophet) remarked: He (Allah) said: Some of My bondsmen entered the morning as My believers and some as unbelievers. He who said: We have had a rainfall due to the Blessing and Mercy of Allah, he is My believer and a disbeliever of stars, and who said: We have had a rainfall due to the rising of such and such (star) disbelieved Me and affirmed his faith in the stars.