It is narrated from Hazrat Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: Miswak is a means of purification for the mouth and the pleasure of Allah, and in black seed (kalonji) there is a cure for every disease except "sam." The companions (may Allah be pleased with them) asked, "O Messenger of Allah! What is meant by 'sam'?" The Prophet (peace and blessings be upon him) replied: Death.