In Salah we need Taharat (cleanliness). Both our body and our clothes must be clean and we should do Ritual washing (Wudu or ablution).
Wudu is the permission for entering Salah and it prepares us spiritually for saying prayers. Without Wudu, our Salah will be invalidated.
Wudu is part of faith and brings light and spiritual attention to the heart. Imam Reza (AS) said one who stands before God in prayer must be clean from impurities and away from frailty and weakness. Wudu prepares the heart for standing before God and praying.
Having Wudu is good not only for Salah but all the time. Even sleeping while one has Wudu is like worshiping at night. The faithful have also been ordered to have Wudu for many other acts of worship such as reading the Quran, reciting supplications, touching the names of Allah and the Infallible (AS), etc.
Apart from cleanliness of the clothes and body and having Wudu, it is necessary for the heart to be free from envy and hatred and for other parts of the body to be free from sins.
Would it not be a kind of hypocrisy if one’s body and clothes are clean but his soul is not?
So on should strive to have phycial and spiritual cleanliness and purity before standing before God for Salah.
Another point is that those who are junub should have a Ghusl (the full-body ritual purification).
If there is a lack of water or time for Wudu and Ghusl, one should do Tayammum.
For Salah, one needs to cover his body, and it is recommended that he or she wear clean, white and fragrant clothes for Salah because they are going to stand before God.
Also, the place where one performs Salah must be Mubah, that is to say, it should not belong to others.
The worshippers should face the direction of the Ka’aba, which is called Qibla. While God is everywhere, facing the direction of the Ka’aba is a reminder of Abrahamic monotheism and the purity of the intention of Abraham (AS) and Ismail (AS) who built the Ka’aba.
Qibla shows the monotheistic direction of Muslims. Not only in Salah, but in supplication, slaughtering animals, sleeping, and burying the dead, facing the Qibla is important.
This is an important lesson that always draws our attention to God and the house of God and strengthens unity among Muslims.