Sūʾ al-ḥifẓ means poor memory. It is the tenth and final cause in the studied list of reasons for unreliability.
A narrator is described as sayyiʾ al-ḥifẓ when, because of poor memory, his incorrect transmissions equal or exceed his correct ones.
• The cause is poor memory.
• Errors equal or exceed correct transmission.
• An occasional single error is not the full definition.