Grading: This report is established as "sahih" from Ka'b al-Ahbar. Ka'b al-Ahbar was previously a Jew; he accepted Islam during the caliphate of Abu Bakr. He used to tell people things from the old (Isra'ili) books and memorised strange and wondrous things, as al-Dhahabi said in "Siyar A'lam al-Nubala'" (3/ 489).
Technical note / Defect ('illah): In "al-Talkhis" al-Dhahabi declared this report defective due to "inqita'" (a break in the chain), i.e. between al-Hasan bin Jabir and Abu al-Zahiriyyah (Hudayr bin Kurayb); but both of them have been corroborated.

Reference / Source: Nu'aym bin Hammad narrated it in abridged form in "al-Fitan" (1648) from Ibn Wahb with this same chain.

Reference / Source: Nu'aym also narrated it (713, 1627), and Ibn 'Asakir in "Tarikh Dimashq" (1/ 244), via the route of Safwan bin 'Amr al-Saksaki, from Abu al-Zahiriyyah alone.

Reference / Source: Abu 'Amr al-Dani narrated it in "al-Sunan al-Waridah fi al-Fitan" (501, 672), al-Rab'i in "Fada'il al-Sham wa Dimashq" (118), and Ibn 'Asakir (1/ 244), via the route of Muhammad bin al-Walid al-Zubaydi, from al-Fudayl bin Fadalah, from Ka'b bin 'Ujrah.

Note / Clarification: "The river of Abu Futrus" is in Palestine; today it is called the 'Awja river and also the Yafa (Jaffa) river, because it flows into the sea to the north of Yafa.