Narrated Abu Said Al-Khudri (Radi-Allahu 'anhu):
Allah's Apostle (Sallallahu 'Alaihi Wa Sallam) used to practice Itikaf (inthe masjid) in the middle third of Ramadan and after passing the twentynights he used to go back to his house on the 21st, and the people who werein Itikaf with him also used to go back to their houses. Once in Ramadan,in which he practiced Itikaf, he established the night prayers at the nightin which he used to return home, and then he addressed the people andordered them whatever Allah wished him to order and said, "I used topractice Itikaf for these ten days (i.e. the middle 3rd but now I intend tostay in Itikaf for the last ten days (of the month); so whoever was inItikaf with me should stay at his place of seclusion. I have verily beenshown (the date of) this Night (of Qadr) but I have forgotten it. So searchfor it in the odd nights of the last ten days (of this month). I also sawmyself (in the dream) prostrating in mud and water." On the night of the21st, the sky was covered with clouds and it rained, and the rain-waterstarted leaking through the roof of the masjid at the praying place of theProphet (Sallallahu 'Alaihi Wa Sallam). I saw with my own eyes the Prophet(Sallallahu 'Alaihi Wa Sallam) at the completion of the morning prayerleaving with his face covered with mud and water.
Bukhari Vol. 3 : No. 235
Fasting - 24th Ramadan 1433 (13th August 2012)