The prerequisite for prayer is ritual purity. The worshipper must not be in a state of janaba and must have performed wudu (or wudu must not have been cancelled since the last ablution). Menstruating women and those with puerperal flow may not perform the ritual prayer. They also do not have to make up the missed prayers.
This is a relief for them. See the subsections on wudu, ghusl, and tayammum in the part on purity. The soiling of clothing by dust and the like does not cause ritual impurity of clothing. See on impurities and their purification (from clothing) in detail in the part on purity.
The clothes must cover the ‘aura of the person praying. The man’s ‘aura goes from the navel to the knee. It is makruh (undesirable) to pray in tight clothing (esp. jeans pants) so that it is stretched over the ‘aura. The clothes must not be transparent so that the aura is visible (i.e. the skin of the corresponding parts of the body).
Moreover, according to a section of scholars, the man must cover his shoulders (or at least one shoulder) during prayer. It is reported from Abu Huraira (r.a.) that the Prophet (Allah’s blessings and peace be upon him) said, “None of you may pray in a single garment that leaves the shoulders uncovered.” (Muslim).
Umar Ibn Abi Salama (r.a.) reported, “I saw the Messenger of Allah, Allah’s blessings and peace be upon him, praying in the house of Umm Salama. He wrapped himself in a single robe, placing its two ends on his shoulders.” The majority considers the prohibition to pray without covering the shoulders as a light prohibition, Imam Ahmad considers the covering to be wajib; according to one view, if one omits the covering, one sins, but the prayer remains valid.
With few exceptions, the whole world is a place of prayer for the Muslim. Abu Sa’id al-Hudrij (r.a.) reported from the Prophet (Allah’s blessings and peace upon him) that the entire earth is a place of prayer except for the gravesites and the toilets. Al-Bara’ ibn ‘Azib reported that the Prophet (Allah’s blessings and peace be upon him) said that one should not pray in the feeding or drinking place for camels.
Abu Huraira, Allah’s pleasure be upon him, narrated, “The Messenger of Allah, Allah’s blessings and salutations be upon him, said, “May Allah condemn the Jews; for they made the graves of their prophets into places of prayer.” Building mosques over graves or placing graves in mosques is forbidden and prayer is invalid when praying in a mosque where there is a grave in the direction of Qibla, because one is not allowed to pray towards a grave.
Many scholars see the prohibition of praying at gravesites as one that merely signifies undesirability; according to some, the prohibition applies only after three graves are located next to each other.
The place of prayer must be free from ritual impurities.
The Imam should not pray in a higher place than those below him, but he is allowed to pray on an elevated place (mimbar) to instruct people in prayer. For the prostration, he descends to make it at the bottom of the minbar. After that, he can go right back up and pray the next rak’a.