Call to Prayers (Adhaan)

Bukhari :: Book 1 :: Volume 11 :: Hadith 605

Narrated Nafi:

Once in a cold night, Ibn 'Umar pronounced the Adhan for the prayer at ,Dajnan (the name of a mountain) and then said, "Pray at your homes", and informed us that Allah's Apostle used to tell the Mu'adhdin to pronounce Adhan and say, "Pray at your homes" at the end of the Adhan on a rainy or a very cold night during the journey."