Abū Zayd al-Anṣārī al-Najjārī, a Medinan, was the most eminent of his brothers—Ismāʿīl, Sulaymān, Yaḥyā, and Saʿd.
His maternal grandfather was Saʿd ibn al-Rabīʿ al-Anṣārī, one of the honored nuqabāʾ (chiefs).
He reported hadith from his father; his uncle Yazīd; Usāmah ibn Zayd; his mother, Umm Saʿd bint Saʿd; Umm al-ʿAlāʾ al-Anṣāriyyah; and ʿAbd al-Raḥmān ibn Abī ʿAmrah.
He was not a prolific narrator.
Those who transmitted from him include his son Sulaymān; his nephew Saʿīd ibn Sulaymān; Sālim Abū al-Naḍr; Abū al-Zinād—his student in jurisprudence—ʿAbd al-Malik ibn Abī Bakr ibn ʿAbd al-Raḥmān ibn al-Ḥārith; ʿAbd Allāh ibn ʿAmru ibn ʿUthmān; ʿUthmān ibn Ḥakīm al-Anṣārī; Mujālid ibn ʿAwf; Muḥammad ibn ʿAbd Allāh al-Dībāj; Ibn Shihāb; Yazīd ibn ʿAbd Allāh ibn Qusayṭ; Abū Bakr ibn Ḥazm; and others.
His transmissions from his uncle are mursal (lacking the Companion link); Mūsā ibn ʿUqbah explained this by saying that his uncle was killed during the caliphate of al-Ṣiddīq. (1)
Al-Wāqidī narrated—through ʿAbd al-Raḥmān ibn Abī al-Zinād, from his father—that the seven jurists to whom people turned for legal opinions in Medina were: Saʿīd ibn al-Musayyib, Abū Bakr ibn ʿAbd al-Raḥmān, ʿUrwah, al-Qāsim, ʿUbayd Allāh ibn ʿAbd Allāh, Khārijah ibn Zayd, and Sulaymān ibn Yasār. (2)
Al-Darāwardī reported—on the authority of ʿUbayd Allāh ibn ʿUmar—that after the Companions of the Messenger of Allah, peace and blessings be upon him, the science of fiqh in Medina resided with Khārijah ibn Zayd ibn Thābit and Saʿīd ibn al-Musayyib.