Sahih Muslim
The Book of Jihad and Expedition (Kitab Al-Jihad wal-Siyar)
Book Number: 019 / Hadith Number: 4445
It has been narrated on the authority of Anas b. Malik that the Messenger of Allah (may peace be upon him) said:
O God, there is no life, but the life of the Hereafter,
So forgive Thou the Ansar and the Muhajirs.