Virtues of the Prayer Hall (Sutra of the Musalla)
Bukhari :: Book 1 :: Volume 9 :: Hadith 480
Narrated Abu Juhaifa:
Allah's Apostle came out at midday and offered a two-Rak'at Zuhr and 'Asr prayers at Al-Batha and an 'Anza was planted in front of him (as a Sutra). He performed ablution and the people took the remaining water left after his ablution and rubbed their bodies with it.