It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that a Bedouin man came to the service of the Prophet (peace and blessings be upon him) and said, "O Messenger of Allah! I stay continuously in desert areas for four or five months. Among us are women in menstruation and postnatal bleeding, and men in a state of major ritual impurity (janabah), (but) we do not find water. What is your opinion?" The Prophet (peace and blessings be upon him) said: "Make the earth obligatory upon yourselves (i.e., perform tayammum)."