Narrated Abu Abdullah Noman bin Bashir: I heard the Messenger of Allah, may Allah bless him and grant him peace, say, ‘Surely the lawful and the unlawful are clear. There are dubious things between the two, most people do not know. Then the person who avoids doubtful matters, he keeps his religion and honor flawless. And the person who engages in suspicious activities is involved in haraam. As a shepherd, his (cattle) animals graze around the protected area. And then there is the fear that any animal will enter it at any time. Be careful! Every king has a reserved area. And God's reserved area is His forbidden things. Be careful! Surely there is a piece of flesh in the human body, when it is healed the whole body is healed and when it is sick the whole body is sick. Know! This is the heart. '(Sahih Muslim, Hadith: 417)
At the end of the hadith in question, the Prophet (peace be upon him) called for self-purification. If the soul is not purified, nothing in human life is managed in a beautiful and healthy way. That is why Allah says, "He who succeeds is the one who purifies his soul, and he who defiles his soul is the loser." (Surah Ash-Shams, verses 8-9)
Various ways and means of purifying the soul are found in the Qur'an-Sunnah. Some of which are:
1. Praying for the purity of the heart: It is necessary to pray to Allah for the purity and purity of the heart and for its firmness in following the rules of Allah. The Prophet (peace and blessings of Allaah be upon him) used to pray, ‘O changer of hearts! Strengthen my heart in your obedience. '(Musnad Ahmad, Hadith: 9420)
2. Not indifferent to the disease of the heart: The Prophet (peace and blessings of Allaah be upon him) said, ‘Surely the heart of man is between the two fingers of Allaah, and He changes it as He wills.’ (Saheeh Muslim, Hadith: 6921)
3. Fear of the Hereafter: Nothing will benefit on the Day of Resurrection except the purification of the soul. So the fear of the Hereafter must be present in the heart. Allaah says (interpretation of the meaning): “Wealth and children will be of no avail to you today except those who come to Allaah with a pure soul.” (Surat al-Shu'ara, 7-89)
Kalbe Salim is the Holy Spirit from shirk and bidat and other ailments and disliked objects. As a result, nothing is left in him except the love and fear of Allah.
4. Mustahab for praying for the health of the heart: The Prophet (peace be upon him) used to pray regularly for self-purification. Therefore, the scholars have said that it is mustahab to pray for self-purification. The Prophet (peace and blessings of Allaah be upon him) used to pray, ‘O Allaah! I wish you a healthy heart. '(Musnad Ahmad, Hadith: 16114)
5. Adopting the method of self-purification as described in the Qur'an-Sunnah: Calling to follow the method of self-purification as described, the Qur'an says, ‘O you who believe! When the Messenger calls you to that which enlivens you, you will respond to the call of Allah and His Messenger. Know! Allah is between man and his heart. '(Surah Anfal, verse: 24)
6. The remembrance of Allah softens the heart: The remembrance of Allah softens and softens the human heart. It is the purification of the soul. The Holy Qur’an says, ‘Know! The remembrance of Allah calms the heart. '(Surah Ra'd, verse: 28)
7 . Staying by the side of helpless people: According to the hadith, a man came to the Prophet (peace be upon him) and complained about the hardness of his heart. The Prophet (peace and blessings of Allaah be upon him) said to him, ‘When you wish to soften your heart, touch the head of the orphan and feed the poor.’ (Musnad Ahmad, hadeeth: 9017)
8. Visiting graves and remembering death: Through visiting graves and remembering death, people's hearts turn to Allah. The Prophet (peace and blessings of Allaah be upon him) said, ‘I forbade you to visit graves before, now you visit them. Because it reminds us of the Hereafter and improves our hearts. '(Musnad Ahmad, Hadith: 23005)
9. Avoiding hardness of heart: In the Qur'an, Allah has condemned hardness of heart in more than one place. Allaah says (interpretation of the meaning): “... Woe to the hard-hearted people who are averse to the remembrance of Allaah. They are in clear error. '(Surah Jumar, verse 22)
10. Remembering the consequences of the defiled soul: The Prophet (peace and blessings of Allaah be upon him) warned of the consequences of defiled souls, saying, ‘Beware! Surely there is a piece of flesh in the human body, when it is healed the whole body is healed and when it is sick the whole body is sick. Know! This is the heart. '(Sahih Muslim, Hadith: 417)