Sahih Bukhari
Call to Prayers (Adhaan)
Volume: 001 / Book Number: 011 / Hadith Number: 597
Narrated 'Abdullah bin Mughaffal Al-Muzani:
Allah's Apostle said thrice, "There is a prayer between the two Adhans (Adhan and Iqama)," and added, "For the one who wants to pray."