Musnad Ahmad 30:1335

Yunus narrated to us, Fulayh narrated to us, from Abdullah ibn Abd al-Rahman, from Sa'id ibn Yasar, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, Allah, the Almighty and Majestic, says: 'Where are those who love one another for the sake of My Majesty? Today, I shall shade them in My shade, on a day when there is no shade but My shade.'"