This hadith is acceptable and its chain of transmission is good, but it is mursal—there is a missing link between Masrūq and Muʿādh.
Ibn Mājah also recorded it through al-Ḥasan ibn ʿAlī ibn ʿAffān,(1) and we possess the same report with a higher chain.
Aḥmad ibn Salāmah communicated it to us in writing, from Khalīl ibn Badr, ʿAlī ibn Fādshāh, and Aḥmad ibn Muḥammad; they said:
“Abū ʿAlī the Qurʾān-reciter informed us; Abū Nuʿaym the ḥāfiẓ informed us; ʿAbd Allāh ibn Jaʿfar related to us; Muḥammad ibn ʿĀṣim narrated to us; Yaḥyā ibn Ādam narrated to us, from Isrāʾīl, from al-Aswad ibn Qays, from Jundub ibn Sufyān, who said:
When Abū Bakr set off with the Messenger of Allah ﷺ toward the cave, he said, ‘Do not enter, O Messenger of Allah, until I have made sure it is safe.’ So Abū Bakr entered the cave, and something struck his hand. He began wiping the blood from his finger while reciting:
You are but a finger that has bled—
and in the cause of Allah is all that you have met.(2)
= Al-ʿAshr, recorded through the chain of Hanad b. al-Sari from Abu Bakr b. ʿAyyash; al-Darimi also transmits it (1/393) through ʿAsim b. Yusuf from Abu Bakr b. ʿAyyash; and Ahmad (5/233) through Sulayman b. Dawud al-Hashimi from Abu Bakr b. ʿAyyash, from ʿAsim, from Abu Waʾil, from Muʿadh, omitting Masruq.
Other narrations on the same subject exist: from Ibn ʿUmar in al-Bukhari (3/274, 276), Abu Dawud (1596), al-Nasaʾi (5/41), and Ibn Majah (1817); from Jabir in Muslim (981) and al-Nasaʾi (5/41–42); and from Abu Hurayra in al-Tirmidhi (639) and Ibn Majah (1816).
al-Duwali is the plural of daliya: an implement made of palm-leaf and wood used to draw water with ropes fastened to the end of a long pole.
(1) The autograph reads: “Ibn Majah and al-Hasan …,” but the correct wording is what we have adopted above.
(2) ʿAbd Allah b. Jaʿfar—the son of Ahmad b. Faris, d. 346 AH—is mentioned in Abu Nuʿaym, Tarikh Isfahan, 2/80. Al-Dhahabi, al-ʿIbar, 2/272, calls him “the hadith scholar of Isfahan and a righteous man.” Muhammad b. ʿAsim, the Thaqafi ascetic of Isfahan (d. 262 AH), about whom Ibrahim Urma said, “He never saw anyone like himself, nor have I seen anyone like him,” is treated in Tahdhib, 9/240–241, and Tarikh Isfahan, 2/189. The remaining transmitters in this isnad are trustworthy. Jundub b. Sufyan is Jundub b. ʿAbd Allah b. Sufyan al-Bajali.
Al-Zarqani, Sharh al-Mawahib, 1/336, attributes the hadith to Ibn Mardawayh.