The Twelver scholars Ahmad ibn Ubayda (d. 941) and Abu Abd Allah al-Ghadhanfari (d. 1020) based their denial of the existence of Sulaym's book on three factors: a segment in the book indicates there were thirteen imams instead of the traditionally held twelve; another segment states Muhammad ibn Abu Bakr condemned his dying father Abu Bakr despite Muhammad being a three-year-old child; and the book was allegedly solely transmitted to Aban ibn Abi Ayyash, despite the fact that the latter was only fourteen-years-old. However, the prominent Twelver scholar al-Hilli rejected theories about Sulaym's non-existence, though Djebli asserts al-Hilli's "arguments were too unconvincing to sweep away such doubts". Nonetheless, later Shi'a biographers produced al-Hilli's arguments verbatim, and Sulaym's book is considered by Shi'a scholars as among the oldest sources of Shi'a thought and superior to the much later four Sunni tradition, namely the Ṣaḥīḥ al-Bukhārī, Ṣaḥīḥ Muslim, Musnad Ibn Ḥanbal and Muwaṭṭaʾ Imām Mālik.
