Is it necessary for someone who performed ablution and recited the remembrances of sleep, then passed wind before sleeping, to repeat ablution? And is that considered like sleeping without purification, or will he be rewarded for following the Sunnah? And is there a difference of opinion on this matter among the four Imams?

Passing wind nullifies ablution (Wudu'), based on the Messenger of Allah (peace be upon him) saying: "The prayer of anyone who passes wind is not accepted until he performs ablution." Abu Hurayrah explained 'passing wind' as breaking wind audibly or silently. There is a difference of opinion regarding whether sleep, when it leads to a minor impurity, nullifies ablution, but the relied-upon view is that it does. As for the ablution of a person in a state of major ritual impurity (junub) for the purpose of sleeping, it is not nullified except by sexual intercourse; this is because it was not prescribed for removing impurity, but rather it is an act of worship, and its reward is only nullified by sexual intercourse.