His grandfather Aḥmad was nicknamed “Silafah,” that is, “thick-lipped.” In Persian the word appears as “Salbah,” and people frequently interchange the letters bāʾ and fāʾ.(1)

Hence the form al-Silafī is to be considered alongside al-Salafī—with two fathas—which denotes one who follows the way of the early generations. Among those called by this nisba are: Abū Bakr ʿAbd al-Raḥmān ibn ʿAbd Allāh al-Sarkhasī, a transmitter from Abū al-Fitiyān al-Rawwāsī.

With a ḍamma on the first letter and a fatha on the second, the adjective becomes al-Sulafī. Examples include Qays ibn al-Ḥajjāj al-Sulafī, Rāfiʿ ibn ʿUqayb, Muḥammad ibn Khālid ibn Khalī, ʿAbd Allāh ibn ʿAbd al-Aʿlā, and Abū al-Akhyal from the line of Sulaf ibn Yaqṭan—a sub-clan of al-Kalāʿ, itself a branch of the Ḥimyar tribe.

With a kasra followed by a sukūn we have al-Silfī: Ismāʿīl ibn ʿAbbād al-Silfī, the cotton-dealer, who narrates from ʿAbbād al-Rawājini.(2) This nisba traces back to Darb al-Silfī, a lane situated in Qaṭīʿat al-Rabīʿ in Baghdad.

Finally, with two fathas and a qāf the form becomes al-Salaqī: Abū ʿAmr Aḥmad ibn Rūḥ al-Salaqī, whom the poet al-Buḥturī satirised.(3)