Musnad Ahmad 402:3

Abdullah ibn Ahmad said: Muhammad ibn Abdullah al-Razi Abu Ja’far narrated to me, he said: Rawh ibn ‘Ata’ ibn Abi Maymunah narrated to us, he said: Sayyar narrated to us, that he heard Khalid ibn Abdullah al-Qasri while he was delivering a sermon on the pulpit, and he was saying: My father narrated to me, from my grandfather, that he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Do you love Paradise?" He said: I said: Yes. He said: "Then love for your brother what you love for yourself."