• On the night of the Isra’, one and a half years before the Hijrah, Allah enjoined upon His Messenger (peace and blessings be upon him) the five daily prayers, and explained that there were conditions and essential parts and other matters having to do with them, bit by bit. Then Jibril came down and taught the Prophet the times of the prayers. • Prayer was enjoined with two Rak`ahs, then when the Prophet migrated, it was enjoined with four Rak`ahs, but prayer while travelling remained as it had originally been. • Before the Isra’, the Prophet definitely used to pray, as did his Companions, but there is a scholarly difference of opinion as to whether any kind of prayer was made obligatory before the five daily prayers or not. It was said that what was obligatory at first was prayer before sunrise and prayer before sunset.

It is permissible to pray in clothes in which one has slept, so long as they are pure and cover the `Awrah, although it is better and more perfect to wear beautiful clothes that look good for prayer.

Why Muslims pray 5 times a day falls into the rules of Shari`ah which are purely worship, the wisdom behind which is concealed from us and is not mentioned in either the Quran or the Sunnah. So we have to submit to the command of Allah.