Abà « Muḥammad al-Ḥasan ibn ûAbd al-RaḥmÃÂn ibn KhallÃÂd al-RÃÂmahurmuzë () (?âÂÂbefore 971 CE/360 AH), commonly referred to in medieval literature as Ibn al-KhallÃÂd, was a Persian hadith specialist and author who wrote one of the first comprehensive books compiled in hadith terminology literature, al-Muḥaddith al-FÃÂá¹£il bayn al-RÃÂwë wa al-WÃÂûë.
Al-RÃÂmahurmuzë's specific date of birth remains undetermined, but can be approximated based upon the dates of his teachers' deaths, placing his birth roughly 100 years prior to his own death. Therefore, 871/260 is a fairly sound estimate, according to The Encyclopaedia of Islam, based on the long life spans generally assumed for early hadith specialists. The name al-RÃÂmahurmuzë is an ascription to RÃÂm-hurmuz a town in Khà «zistÃÂn in present-day south-western Iran. The significance of RÃÂm-hurmuz was its central location at the intersection of AhwÃÂz, Shà «shtar, Iá¹£fahÃÂn and FÃÂrs between the ÃÂb -i KurdistÃÂn and the Gà «pÃÂl rivers.
He first began his hadith studies in 903/290, hearing hadith from his father, ûAbd al-RaḥmÃÂn ibn KhallÃÂd, and Muḥammad ibn ûAbdillÃÂh al-Ḥaá¸Âarë, Abà « al-Ḥuá¹£ayn al-WÃÂdiûë, Muḥammad ibn ḤibbÃÂn al-MÃÂzinë and others from their generation. He worked as a judge (qÃÂá¸Âë) for a period of time, although little detail is provided. Al-Dhahabi described Al-RÃÂmahurmuzë as "the distinguished imam...who was from the imams of hadith and this will be apparent to anyone who reflects upon his work in the science of hadith."
His students include Abà « al-Ḥusayn Muḥammad ibn Aḥmad al-á¹¢aydÃÂwë, al-Ḥasan ibn al-Layth al-ShërÃÂzë, Aḥmad ibn Mà «sàibn Mardawayh, Aḥmad ibn IsḥÃÂq al-NahÃÂwandë and numerous others from the inhabitants of Persia.
Al-Dhahabi said he was unable to find the date of Al-RÃÂmahurmuzë's death and speculated it to have been during the 350s AH, between 961 and 971 CE. He then quoted Abà « al-QÃÂsim ibn Mandah as mentioned in his work, al-WafayÃÂt, that Al-RÃÂmahurmuzë lived until almost 971/360 while living in the city of RÃÂm-hurmuz. The Encyclopaedia of Islam specified his death as occurring in 971/360.
Al-RÃÂmahurmuzë was a poet and a few lines of his poetry were collected in Yatëmah al-Dahr by al-ThaûÃÂlabë. Two of his works of prose remain until the present, both concerning the subject of hadith.