Maliks Muwatta Book 13, Hadith Number 4.

Section : About Asking the Stars for Rain.

Yahya related to me from Malik from Salih ibn Kaysan from Ubaydullah ibn Abdullah ibn Utba ibn Masud that Zayd ibn Khalid al-Juhani said, “The Messenger of Allah, may Allah bless him and grant him peace, took the subh prayer with us at Hudaybiyya after it had rained in the night. When he had finished he went up to the people and said, ‘Do you know what your Lord has said?’ They said, ‘Allah and His Messenger know best.’ He said, ‘Some of my slaves have begun the morning believing in Me, and others have begun it rejecting Me. As for those who say, ‘We were rained on by the overflowing favour of Allah and His mercy,’ they believe in Me and reject the stars. But as for those who say, ‘We were rained on by such and such a star, they reject Me and believe in the stars.'”