Musannaf Ibn Abi Shayba 36:109

Ali ibn Mushir narrated to us, from al-Ajalh, from al-Sha'bi, who said: The Messenger of Allah, may Allah bless him and grant him peace, arrived when he conquered Khaybar. It was said to him, "Ja'far has arrived from the Negus." He said, "I do not know for which of the two I am more joyful: the arrival of Ja'far or the conquest of Khaybar." Then he met him, embraced him, and kissed him between his eyes.