Sahih Bukhari
Call to Prayers (Adhaan)
Volume: 001 / Book Number: 011 / Hadith Number: 635
Narrated Nafi':
Once on a very cold and stormy night, Ibn 'Umar pronounced the Adhan for the prayer and then said, "Pray in your homes." He (Ibn 'Umar) added. "On very cold and rainy nights Allah's Apostle used to order the Mu'adhdhin to say, 'Pray in your homes.' "