Musnad Ahmad 435:54

Yahya ibn Ishaq narrated to us, he said: Ibn Lahi'ah informed us, from Ja'far ibn Rabi'ah, from Rabi'ah ibn Yazid, from 'Amir ibn 'Abd Allah al-Yahsubi. 'Abd Allah said: My father said: "Thus said Yahya ibn Ishaq, and it is only 'Abd Allah ibn 'Amir al-Yahsubi." He said: I heard Mu'awiyah ibn Abi Sufyan saying: I heard the Prophet, may Allah bless him and grant him peace, saying: "A group of my Ummah will continue to be upon the truth; they will not be harmed by those who oppose them or those who forsake them, until the command of Allah, the Almighty and Majestic, comes."