Narrated Anas: The Prophet offered a four-Rak'at Zuhr prayer at Medina and then offered a two Rak'at 'Asr prayer at Dhul-Hulaifa and I heard the companions of the Prophet reciting Talbiya aloud (for Hajj and 'Umra) altogether.
— Sahih Bukhari, Volume 4, Book 52: Fighting for the Cause of Allah (Jihaad), Hadith #200
