It is narrated from Hazrat Asma bint Umais (may Allah be pleased with her) that once the Prophet (peace and blessings be upon him) asked me, "Which medicine do you use as a laxative?" I replied, "Shabram" (which is the name of a herb). The Prophet (peace and blessings be upon him) said, "It is very hot." Then I started using the herb called "Sana" as a laxative. The Prophet (peace and blessings be upon him) said, "If there were a cure for death in anything, it would be in Sana."