Adabus Salat - Sayyid Ruhullah Khomeini
"Know that for the salat (daily prayer), beside its form, there is a meaning, and apart from its exterior it has an interior; and as the exterior has its disciplines, neglecting which would render the outer form of the salat invalid or incomplete, likewise its interior has cordial spiritual disciplines, neglecting which would render the spiritual salat invalid or incomplete; whereas observing them would inspire the salat with a heavenly spirit. It would be possible that after paying attention to and observing the cordial inner disciplines, the musalli (worshipper) would have a share of the divine secret of the salat of the "people of knowledge and of hearts" - the salat which is the delight of the people of suluk (wayfaring) and the reality of the mi'raj (ascension) to the proximity of the Beloved." - Sayyid Khomeini