Musnad Ahmad 82:0

Narrated to us by Hisham, who said: Narrated to us by Ma'mar, from Az-Zuhri, from 'Ubaydullah bin 'Abdullah, from Ibn 'Abbas, who said: 'Ayyash bin Abi Rabi'ah said: "The Messenger of Allah (ﷺ) said to me: 'If you see the people of the Levant (Ash-Sham) having perished, then there is no good in you. And a group of my Ummah will continue to be victorious, not harmed by those who forsake them, until the Hour is established.'"