Ibrāhīm ibn al-Mahdī, famous musician, is a main character of a great number of aḫbar in medieval Arabic literature. One of them tells about his adventure as an uninvited guest, who enters merchant’s house attracted by a beautiful girl. Victor Chauvin entitled this story "Mariage d’Ibrāhīm" and similarly its version in which Isḥāq ibn Ibrāhīm al-Mawṣilī plays a key role - "Mariage d’Isḥaq". The story and its versions are widespread in a dozen or so works which were produced within over seven hundred years. The earliest account is preserved in Ibn cAbd Rabbihi’s Al-Iqd al-farīd. The aim of this research is to try to indicate the probable source aḫbār which inspired medieval Arabic transmitters and story-tellers to create the account.