Musnad Ahmad 2:43

Yahya ibn Ishaq narrated to us, Ibn Lahi'ah narrated to us, from Abu al-Zubayr, from Jabir, who said: 'Umar ibn al-Khattab informed me, saying: I heard the Prophet, peace and blessings of Allah be upon him, saying: "A rider will surely travel along the outskirts of Medina, then he will say: 'There used to be many of the believers present in this place.'" My father, Ahmad ibn Hanbal, said: Hasan al-Ashyab did not attribute it to Jabir.