[The Absolute Singularity]

The first category is the absolute singular report: for instance, the ḥadith that forbids selling or gifting walāʾ (the right of allegiance); it was transmitted solely (1) by ʿAbd Allah ibn Dīnār from Ibn ʿUmar (2).

A report may also be narrated singly (3) by one transmitter from that original single authority (4), that is, one person alone (5) relates it. An example is the ḥadith on the “branches of faith”: it was narrated only by Abū Ṣāliḥ from Abū Hurayrah, and only by ʿAbd Allah ibn Dīnār from Abū Ṣāliḥ (6).

This singleness may persist throughout all—or most—of the transmitters in the chain. The Musnad of al-Bazzār (7) and al-Ṭabarānī’s al-Muʿjam al-Awsat (8) contain many such examples.

[The Relative Singularity]

The second category is the relative singular report (9). It is called “relative” (10) because the singleness in it (11) is with respect to a particular individual, even though the ḥadith itself may be widely circulated.