Musnad Ahmad 333:23

Ibrahim ibn Mahdi narrated to us, he said: Hatim—meaning Ibn Isma'il—narrated to us, from Yazid ibn Abi 'Ubayd, who said: I heard Salamah ibn al-Akwa' saying: I went out, and he mentioned the like of the hadith of Makki, except that he said: "And today is the day of the sucklings [al-rudda']." And he added in it: And the Messenger of Allah, peace and blessings of Allah be upon him, let me ride behind him on his mount.