The Stages of Purification

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So, the first stage of purity is the observance of divine laws and the obedience to Allah's commands.

The second stage is to be adorned with virtuous morals and faculties.

The third stage is the purity of the heart, which means submitting the heart to Allah, after which the heart becomes luminous, or rather it becomes of the world of light and a degree of divine light. The luminosity of the heart flows to other organs and inner powers, and the whole kingdom turns into light, and light upon light, till the heart becomes divine and godly and the Divinity [hadrat-i lahut] manifests in all the inner and outer stages. In this case, servitude completely vanishes and is annihilated, and Lordship explicitly appears, in which case, the heart of the salik is overcome by a state of tranquillity and familiarity, and he loves the whole world, and experiences divine trances, and the sins and faults become forgive-able to him, and will be covered by the shelter of "love manifestations" [tajalliyat-i hubbi], and primary holiness [wilayat] begins to appear in him, and he becomes worthy of attending "the Presence of Intimacy" [mahdar-i uns]. Then, there are other stages, mentioning which does not suit these papers.

Taken From Adabus Salat by Imam Khomeini