: In the case in question, if the lower part of your waist is well attached to the seat while sleeping in the seat, it will be considered that the ayu has not been damaged. In this case, it has become saheeh to perform the Asr prayer with that ablution. However, in such cases, it is better to perform ablution again as a precaution. And if the lower part of the waist is separated from the seat while sleeping, then the ayu will be considered to be ruined. In that case that prayer has to be read again. (Badayous Sanaye 1/135 ; Fatawa Khaniya 1/41 ; Khulasatul Fatawa 1/19)