Musnad Abu Ya'la al-Mawsili 111:34

Shu'ayb ibn Salamah ibn Qasim al-Ansari, from the descendants of Rifa'ah ibn Rafi' ibn Khadij, narrated to us, saying: Abu Mus'ab Isma'il ibn Qays ibn Zayd ibn Thabit narrated to us, Abu Hazim narrated to us, from Sahl ibn Sa'd al-Sa'idi, who said: Al-Abbas ibn Abd al-Muttalib sought permission from the Prophet, may Allah bless him and grant him peace, to emigrate. He said to him: "O my uncle, remain in your place where you are, for Allah, the Almighty and Majestic, will conclude the emigration with you, just as He concluded the Prophethood with me."