Musannaf Ibn Abi Shayba 33:1105

Affan narrated to us, he said: Abu 'Awanah narrated to us, from Yazid, from Abdullah ibn al-Harith, who said: Ka'b said: Allah never looked at Paradise except that He said, "You have become good for your people," so it increased in goodness beyond what it already was, until its people enter it.