478 — ʿAbd al-ʿAzīz ibn Bahr narrated to me: Abū ʿAqīl informed us, from Muhammad ibn Nuʿaym, the freedman of ʿUmar ibn al-Khattāb, from Muhammad ibn ʿUmar ibn ʿAlī ibn Abī Tālib, from his grandfather ʿAlī—may Allah be pleased with him—who said: “The gravest of sins in the sight of Allah is a lying tongue, and the worst regret is the regret of the Day of Resurrection.”