I heard one of the companions of Abdullah [bin al-Mubārak] say, Ibn al-Mubārak said ‘What an excellent man is Baqiyyah, if it were not for the fact that he would provide a nickname for [those who were better-known by] the birth name, and he would provide the birth name for [those who were better-known by] a nickname. For a long time he would narrated to us on authority of Abī Sa’īd al-Wuhāthī, then when we investigated [we were surprised that] he was Abd ul-Quddūs ’.