The Sufi cloak (ḥırqa-yı taṣawwuf, the cloak of Sufism) is the garment worn by the murīd (aspirant, disciple) who enters under the authority of the shaykh and repents at his hand due to various spiritual states (aḥwāl).
One of its outcomes is that, just as the shaykh clothes the outward form of the disciple, he also clothes his inward being with his own attributes, so that the disciple may don the garment of spiritual aspiration (murād). Thus, this is the garment of taqwa (God-consciousness), both outwardly and inwardly. Allah says: O children of Adam! We have bestowed upon you clothing to conceal your private parts and as adornment. But the clothing of taqwa... that is best. (al-Aʿrāf 7:26)
Another outcome is that the blessing (baraka) of the shaykh reaches the murīd to whom he has given the garment with his blessed hand.
Another is that, during the investiture of the garment, the murīd attains the spiritual state (ḥāl) that prevails over the shaykh. This is such a ḥāl that, with the aid of the sacred light (nūr), the shaykh, through his deep and illuminating insight (baṣīra), perceives that the murīd is in need of his shaykh in order to remove the veils that prevent him from witnessing the Real (al-Ḥaqq) and to purify his inclinations. When the shaykh becomes aware of the state of the one repenting in his presence, he knows, by the light of the Real, what that person needs. He asks Allah for light to descend into the heart of the disciple, and for it to flow from his own inward being to that of the murīd, until the disciple's heart is characterized by it.
Another outcome is the union (wuṣla) between the murīd and the shaykh. For this reason, the spiritual bond between them becomes constant. The murīd, until he reaches the limit of maturity, remembers his shaykh as a true father in his conduct, actions, character (akhlāq), and spiritual states (aḥwāl). This is as in the hadith of the Prophet (peace be upon him): "Fathers are three: the one who caused your birth, the one who taught you, and the one who raised you." (Kāshānī, 159; Jāmiʿ, 82)