Sahih Bukhari
Holding Fast to the Quran and Sunnah
Volume: 009 / Book Number: 092 / Hadith Number: 440
Narrated Anas:
The Prophet brought the Ansar and the Quarish people into alliance in my house at Medina, and he invoked Allah for one month against the tribe of Bani Sulaim in (the last Rak'a of each compulsory) prayer.