How does one purify his heart?

The purity of the heart is the foundation for the soundness and uprightness of the limbs, and it is the path to happiness in this world and the Hereafter, as stated in the prophetic Hadith (definition): "Indeed, there is a piece of flesh in the body which, if it is sound, the whole body is sound, and if it is corrupt, the whole body is corrupt. Indeed, it is the heart."

The heart is corrupted by many diseases such as love of this world, hypocrisy, rancor, and envy, while it is adorned by obligatory deeds such as sincerity, love of Allah, fear of Him, hope in Him, and reliance upon Him.

It is recommended to review the sections on "The Destructive Vices and the Saving Virtues" in Al-Ihya, and the book "Madarij al-Salikin" by Ibn al-Qayyim. Among the greatest causes for the rectification of the heart is to occupy it with thoughts that benefit, to repel evil thoughts, to ponder over Allah's Names, Attributes, and blessings, and to reflect on the Quran and be attentive during its recitation, for that heals the heart and makes it turn towards Allah.