“Invoking strengthens the heart and the body, puts inner and outer affairs in order, gladdens the heart and face, making the latter radiant. Moreover, it procures sustenance and facilitates obtaining it. It clothes the invoker with dignity; it inspires correct behavior in every affair. Its permanence is one of the means of obtaining the love of God; it is one of the greatest gateways leading to that love. Invoking causes the vigilance that leads to the station of spiritual virtue, wherein the servant adores God as if he saw Him with his very own eyes. It causes one to turn to God often; for whoever turns to God by remembering Him frequently will eventually turn to Him in all his affairs. Invoking brings closeness to the Lord and opens the door of gnosis within the heart. It bestows on the servant the veneration and reverential fear of his Lord…The invocation is the nourishment of the soul just as food is the nourishment of the body. Invoking polishes the heart of its rust, which is forgetfulness and the pursuit of its passions.”
– Ibn Ata Allah Al-Iskandari, The Key to Salvation and the Lamp of Souls