When the kunyah and the nisbah are the same. Two men were called Abū ʿImrān al-Jawnī: ʿAbd al-Malik, a tābiʿī, and Mūsā ibn Suhayl al-Baṣrī. Three men bore the name Abū Bakr ibn ʿAyyāsh: the Qurʾān-reciter, the Ḥimṣī— from whom Jaʿfar ibn ʿAbd al-Wāḥid transmitted— and the Sullamī al-Bājjadāʾī.

The converse, where the name and the father’s name coincide but the kunyah and nisbah differ, such as Ṣāliḥ ibn Abī Ṣāliḥ; there are four of them: the client of al-Tuʾamah; the one whose father was Abū Ṣāliḥ as-Salman; the Sadūsī who narrated from ʿAlī and ʿĀʾishah; and the freedman of ʿAmr ibn Ḥurayth.

Complete agreement in their names, their fathers’ names, and their nisbahs, for example: Muḥammad ibn ʿAbdallāh al-Anṣārī, the well-known judge from whom al-Bukhārī narrated, and a second, Abū Salamah, who is weak.

Agreement in the personal name or the kunyah alone, as with the names Ḥammād, ʿAbd Allāh, and the like. Salamah ibn Sulaymān said: “If the people of Mecca mention ‘ʿAbd Allāh,’ they mean al-Zubayr; in Medina, they mean Ibn ʿUmar; in Kūfah, Ibn Masʿūd; in Baṣra, Ibn ʿAbbās; and in Khurāsān, Ibn al-Mubārak.” Al-Khalīlī added: “If an Egyptian uses it, he intends Ibn ʿAmr, while a Meccan intends Ibn ʿAbbās.” Some ḥuffāẓ observed that in the isnād “Shuʿbah narrates from Shuʿbah from Ibn ʿAbbās,” every transmitter called Abū Ḥamzah—spelled with ḥāʾ and zāʾ—except for Abū Jamzah, spelled with jīm and rāʾ, namely Naṣr ibn ʿImrān al-Ḍubʿī; and when the name is left unqualified, the one with jīm is meant.

Agreement in the nisbah alone, such as al-Āmilī. Al-Samʿānī said: “Most scholars of Ṭabaristān come from its city Āmul, yet the person famous for the nisbah to Āmul on the Jayḥūn is ʿAbd Allāh ibn Ḥammād, the teacher of al-Bukhārī. Abū ʿAlī al-Ghassānī—followed by Qāḍī ʿIyāḍ—was mistaken when he claimed that the nisbah referred to Āmul of Ṭabaristān.” Another illustration is the nisbah al-Ḥanafī, which may refer either to Banū Ḥanīfah or to the legal school. Many ḥadīth scholars attach it to the school, writing it Ḥanifi with an extra yāʾ, and among the grammarians only Ibn al-Anbārī supported them.