Musnad Abu Ya'la al-Mawsili 109:179

Abdullah ibn Umar ibn Aban narrated to us, Muhammad ibn Fudayl narrated to us, from al-Walid ibn Jami’, from Abu Salamah, from Jabir, who said: The Messenger of Allah (may Allah bless him and grant him peace) stood among us one day upon the pulpit and said: "While some people were traveling at sea, the Jassasah met them. I said: 'And what is the Jassasah?' He said: 'A woman dragging the hair of her skin and her head. She said: "In this palace is news of what you desire." So they came to it, and behold, they were with a man bound in chains. He said: "Inform me, or ask me, and I will inform you." The people remained silent. He said: "Inform me about the palm trees of Baysan, the spring of Zughar, and Amman; have they borne fruit?" They said: "Yes." He said: "Then inform me about the swamp of Zughar; is there water in it?" They said: "Yes, it is full and overflowing on its side." He said: "And he is the Messiah; the earth is folded for him, so he traverses it in forty [days], except for Tayyibah." The Messenger of Allah (may Allah bless him and grant him peace) said: "It is al-Madinah. There is no gate among its gates except that there is an angel upon it, drawing his sword, preventing him from it. And in Makkah, there is the like of that." Then he said: "In the Persian Sea, what is it? In the Roman Sea, what is it?" [He said it] three times. He said: Then Ibn Abi Salamah said: "Indeed, in this hadith is something I did not memorize." He said: "Then Jabir testified that it is Ibn Sayyad." I said: "But Ibn Sayyad has died." He said: "Even if he died." I said: "But he had accepted Islam." He said: "Even if he had accepted Islam." I said: "But he had entered al-Madinah." He said: "Even if he had entered al-Madinah."