The book Sirrul Asrar reviews the foundations of Islamic spirituality in a straightforward manner. The basic teachings of Islam—prayer, fasting, zakat, and hajj—are explored in depth of their meaning and their close relationship to our journey in life as servants of Allah. Sheikh al-Jailani guides us to understand the secrets and what is behind the secrets. Sheikh takes us to explore the traces of God that lie in the universe and within us; directs us to the depths of nature and unity with the Essence. Not a few scholars have written books on Sufism, but Sheikh al-Jailani explains this spiritual path more concisely and is easily digested by a wide audience.

And among the contents it also discusses Purification, namely self-cleaning. There are two kinds of purity, namely external purity which is obtained through purification as prescribed by religion, such as ablution and bathing, and inner purity which is obtained through awareness and repentance for all dirt and sin. Birth purity will be realized if we truly repent. Inner purification requires spiritual guidance from a teacher.

According to religious law and teachings, a person becomes dirty and his ablution is invalidated if certain materials such as feces, urine, vomit, fart, blood, sperm, and so on, come out of his body. He had to perform ablution again. If what comes out is sperm and is due to menstruation, she must bathe. In other cases, certain parts of the body – such as hands, elbows, face and feet – must be pure.

Rasulullah saw. said:

"Every time someone renews his ablution, Allah renews his faith so that the light of his faith becomes brighter and brighter."

In another hadith he said:

“Ablution is light upon light.”

Like external purity, inner purity can also be lost – perhaps more often – due to bad morals, despicable behavior, and harmful actions and attitudes, such as arrogance, arrogance, lying, backbiting, slander, envy and anger. Actions carried out by the senses, whether intentional or not, can damage the soul: the mouth that eats unclean food. Lips that lie and curse, ears that listen to gossip or slander, hands that injure, or feet that indulge in injustice.