Musnad Ahmad 830:46

Yazid narrated to us, Hammad ibn Salamah informed us, from Ali ibn Zayd, from Abd al-Rahman ibn Abi Bakrah, from his father, who said: The Messenger of Allah (ﷺ) said: "The parents of the Dajjal will remain for thirty years without a child being born to them. Then a one-eyed boy will be born to them, the most harmful of things and the least beneficial. His eyes will sleep, but his heart will not sleep." Then he described his parents, saying: "His father is a tall man, with flabby flesh, and a long nose, as if his nose were a beak. His mother is a woman with heavy breasts." He said: "It reached us that a child was born to the Jews in Medina." He said: So I and al-Zubayr ibn al-Awwam set out until we entered upon his parents, and we saw in them the description of the Messenger of Allah (ﷺ). He was lying in the sun, wrapped in a velvet blanket, murmuring. We asked his parents, and they said: "We remained for thirty years without a child being born to us, then a one-eyed boy was born to us, the most harmful of things and the least beneficial." When we left, we passed by him, and he said: "What were you in?" We said: "Did you hear?" He said: "Yes, my eyes sleep, but my heart does not sleep." And he was Ibn Sayyad.