Musnad Abu Ya'la al-Mawsili 117:6

Wahb ibn Baqiyyah al-Wasiti narrated to us, Khalid narrated to us, from Yunus ibn Ubayd, from Thabit, from Anas, who said: A man came to the Prophet, may Allah bless him and grant him peace, and said: "A man loves a people for the good deeds they perform, but he has not performed the like of them." The Prophet, may Allah bless him and grant him peace, said: "A person is with whom he loves," or "with whom he loves." He said: The companions of the Prophet, may Allah bless him and grant him peace, rejoiced at that with a joy the likes of which I have not seen them rejoice at anything.