I have found no definitive record of his death; it is only reported that he passed away sometime in the early 560s AH.

347 – Naṣr ibn Sayyār ibn Ṣāʿid ibn Sayyār, Abū al-Fatḥ al-Kinānī (1)

The shaykh, the imām, the jurist, a centenarian, the senior ḥadith transmitter of Khurasan, Sharf al-Dīn, Abū al-Fatḥ al-Kinānī, al-Harawī, the Ḥanafī, the judge.

He studied extensively with: his grandfather, the judge Abū al-ʿAlāʾ Ṣāʿid ibn Sayyār ibn Yaḥyā ibn Muḥammad ibn Idrīs; the judge Abū ʿĀmir Maḥmūd ibn al-Qāsim al-Azdī—​from whom he heard the Jāmiʿ of Abū ʿĪsā (al-Tirmidhī); Najīb ibn Maymūn al-Wāsiṭī; the ascetic Muḥammad ibn ʿAlī al-ʿUmayrī; Abū ʿAṭāʾ ʿAbd al-Aʿlā ibn ʿAbd al-Wāḥid al-Malīḥī; Abū Naṣr Aḥmad ibn Amīrjah; and a number of others.

He also received written authorisations (ijāzahs) from Shaykh al-Islām Abū Ismāʿīl al-Anṣārī and from Abū al-Qāsim Aḥmad ibn Muḥammad al-Khalīlī.

In addition, he heard from his grandfather the Ṣaḥīḥ of al-Ismāʿīlī.

Al-Samʿānī says in al-Taḥbīr (2): “I heard from him the Jāmiʿ of al-Tirmidhī and the Kitāb al-Zuhd of Saʿīd ibn Manṣūr, which he had related from his grandfather.”

He also states (3): “He was a jurist, a capable debater, virtuous, devout, of praiseworthy conduct, naturally poised, free of affectation, and blameless. He was born in 475 AH.”