Invoking Allah for Rain (Istisqaa)

Bukhari :: Book 2 :: Volume 17 :: Hadith 130

Narrated Anas bin Malik:

A man came to Allah's Apostle and said, "O Allah's Apostle! Livestock are destroyed and the roads are cut off. So please invoke Allah." So Allah's Apostle prayed and it rained from that Friday to the next Friday. Then he came to Allah's Apostle I and said, "O Allah's Apostle! Houses have collapsed, roads are cut off and the livestock are destroyed." So Allah's Apostle (p.b.u.h) prayed, "O Allah! (Let it rain) on the tops of mountains, on the plateaus, in the valleys and over the places where trees grow." So the clouds cleared away from Medina as clothes are taken off.