Grading: This report is sahih, while the present chain is da'if (weak) due to the weakness of Ali bin Zayd (Ibn Jud'an). But the story which the author (al-Hakim) has not mentioned here is authentically established through another route, which will come at number (5901) from Ammar bin Abi Ammar: When Zayd bin Thabit died, we sat with Ibn Abbas in the shade of a palace, and he said: "This is how knowledge departs; a great deal of knowledge has been buried today."

Identification of names: Abu Abd Allah Muhammad bin Ali is Muhammad bin Ahmad bin Ali bin Makhlad al-Jawhari. The author has narrated several reports from him through al-Harith bin Abi Usamah, and in some of them (as here) he attributed him to his grandfather. Abu Amir al-Khazzaz is Salih bin Rustum.

Reference / Source: Al-Tabarani narrated it in "al-Mu'jam al-Kabir" (4751) through the route of Malik bin Sa'd al-Qaysi, from Rawh bin Ubadah, with this chain, and mentioned the story.

Reference / Source: Abu Nu'aym narrated it in "Ma'rifat al-Sahabah" (2905), and through his route Ibn Asakir (19/334), through Abu Bahr Abd al-Rahman bin Uthman al-Bakrawi, from Abu Amir al-Khazzaz, with this chain.

Reference / Source: Abu al-Qasim al-Baghawi narrated it in "Mu'jam al-Sahabah" (862), and through his route Ibn Asakir (19/335), through the route of Sufyan bin Uyaynah, from Ali bin Zayd bin Jud'an.

Note / Clarification: It will come later at number (5900) through the route of Ma'mar bin Rashid from Ibn Jud'an: "When Ibn Abbas buried Zayd bin Thabit…" In it there is no mention of Sa'id bin al-Musayyab.