Clarification: In the manuscripts and the sources of takhrij it is "Yazid bin Khumayr" (with kha' and ra'), whereas the sources for the biography of Sulayman bin Marthad state that no one narrated from him except Abu al-Tayyah Yazid bin Humayd (with ha' and dal). In any case, both narrators are thiqah (trustworthy).

Grading: Its chain is weak.
Technical note / Defect ('illah): 1. Sulayman bin Marthad (al-Ghanawi): there is "jahalah" (unknown status) in him, and no one other than Ibn Hibban is reported to have declared him trustworthy, nor is it known that he heard from Abu al-Darda' (as al-'Uqayli and al-Dhahabi said), and it will come that there is an unnamed intermediary between the two. 2. There is disagreement over it from Shu'bah as to whether it is marfu' or mawquf, and the mawquf is the more correct (asahh), as Abu Hatim al-Razi said in "al-'Ilal" (1792).

Reference / Source: Al-Bayhaqi recorded it in "Shu'ab al-Iman" (772) from Abu Abdullah al-Hakim, with this same chain.

Reference / Source: 'Abd bin Humayd (210), Abu Hatim al-Razi (al-'Ilal 1792), Abu Dawud in "al-Zuhd" (after 204), al-'Uqayli in "al-Du'afa'" (595), Ibn al-A'rabi in his "Mu'jam" (1123), al-Bayhaqi (772) and Ibn 'Asakir in "Tarikh Dimashq" (52/ 216) recorded it through various routes from Muslim bin Ibrahim, with this same chain.

Reference / Source: Al-Bazzar (4124) recorded it via al-Hasan bin Yahya and Abd al-Malik bin Muhammad al-Raqashi, from Muslim bin Ibrahim.
Technical note / Defect ('illah): But he added (contrary to the other narrators from Muslim bin Ibrahim) "the daughter of Abu al-Darda'" between Sulayman bin Marthad and Abu al-Darda'. Al-Bazzar said: "We do not know anyone who narrated this hadith from Shu'bah with a full chain to the Prophet except Muslim, whereas a group other than Muslim narrated it from Shu'bah and made it mawquf on Abu al-Darda'."

Technical note / Defect ('illah): Muslim (bin Ibrahim) was contradicted by Yahya bin Abi Bukayr, as recorded by Ibn Abi Shaybah (13/ 312) and al-'Uqayli (after 595).
Details of the narration: He narrated it from Shu'bah, from Yazid bin Khumayr, from Sulayman bin Marthad, who said: I heard the daughter of Abu al-Darda' narrating from Abu al-Darda', as "mawquf".

Technical note / Defect ('illah): Both of them were contradicted by Hafs bin 'Umar al-Hawdi, as recorded by Abu Hatim al-Razi (al-'Ilal 1792) and Abu Dawud in "al-Zuhd" (204).
Details of the narration: He narrated it from Shu'bah, from Yazid bin Khumayr, from Sulayman bin Marthad, from the grandson (son of the daughter) of Abu al-Darda', from Abu al-Darda', as "mawquf".
Grading: After it Abu Hatim said: This is more likely, and its being "mawquf" is more correct; the companions of Shu'bah do not narrate this hadith as marfu'.

Corroborating chains and supporting reports: On this topic there are narrations from more than one Companion, but without the words: "You do not know whether you will be saved or not be saved." Among them are Anas bin Malik (al-Bukhari 4621, Muslim 2359), 'A'ishah (al-Bukhari 5221, Muslim 901) and Abu Hurayrah (al-Bukhari 6485), and the narration of Abu Dharr has already passed with the author (al-Hakim) at number (3927).