It is narrated from Sayyiduna al-Hirmas bin Ziyad (may Allah be pleased with him). The narrator (Ikrimah bin Ammar) said: I set out for Hajj and reached al-Muqtarab, the Muqtarab of Bahilah, where I met al-Hirmas bin Ziyad (may Allah be pleased with him). He told me, saying: "I saw the Messenger of Allah (peace and blessings be upon him) at Mina on a she-camel, and al-Fadl bin Abbas (may Allah be pleased with them both) was riding behind him."
Hadith Referenceالمعجم الكبير للطبراني / باب الهاء / 18752