Musnad Abu Ya'la al-Mawsili 155:30

Kamil ibn Talhah narrated to us, Ibn Lahi'ah narrated to us, 'Amr ibn Shu'ayb narrated to us, from Sa'id ibn al-Musayyib, from Abu Hurayrah, that men came to the Messenger of Allah (may Allah bless him and grant him peace) and said: "We are people who stay in the sands, and major ritual impurity (janabah) befalls us, and among us are those who are menstruating and those who are experiencing postpartum bleeding, and we do not find water for four months or five months." The Prophet (may Allah bless him and grant him peace) said: "You must use the earth."