Abd al-ʿAzīz ibn Abī Salamah and Yaḥyā ibn Sulaym narrated this ḥadīth from Jaʿfar ibn Muḥammad, from his father, from ʿAlī, from the Prophet ﷺ(1).

The practice according to this is held by some of the people of knowledge among the Companions of the Prophet ﷺ and others. They held that the oath along with a single witness is permissible in claims and financial matters. This is the view of Mālik ibn Anas, al-Shāfiʿī, Aḥmad, and Isḥāq. They said: Judgment is not given on the basis of the oath along with a single witness except in claims and financial matters.

Some of the people of knowledge among the people of Kūfah(3) and others did not hold that judgment should be given on the basis of the oath along with a single witness.

14 - Chapter: What has been reported concerning a slave shared between two men, one of whom frees his share

1395 - Aḥmad ibn Manīʿ narrated to us, saying: Ismāʿīl ibn Ibrāhīm informed us, from Ayyūb, from Nāfiʿ--------------------------------------------
= Jaʿfar ibn Muḥammad may have sent this ḥadīth (i.e., narrated it without a full chain), and he may have connected it from Jābir, because a group of trustworthy narrators preserved it from his father, from Jābir. The accepted view is theirs, because they added to it and they are trustworthy.
(1) Its chain is disconnected, because Muḥammad, the father of Jaʿfar, did not hear from ʿAlī. Al-Dāraquṭnī recorded it in 4/1212.
(2) In (B) and (S): permissible.
(3) In al-Tamhīd 2/153: Abū Ḥanīfah and his companions, al-Thawrī, and al-Awzāʿī said: Judgment is not given on the basis of the oath along with a single witness. This is also the view of ʿAṭāʾ, al-Ḥakam ibn ʿUtaybah, and a group.