Assalam alaikum,
The prayer, as-salat, requires purification of the body with clean water, with which to perform the ablution. Outwardly, when we perform the ablution, we wash our hands, mouth, face, wiping the head and the two feet.
Inwardly, when we wash our hands, we must thereby THINK and take it to MEAN we wash our HEART(S) clean of worldliness, and when we put water in our mouth to clean it, we thereby PURIFY it from mentioning of other than God, and when we wash our face(s), we must turn away from all familiar objects and turn towards Him, Allahu Tabaraka Wa Ta'ala, and by wiping our heads, we must resign our affairs to God, and when we wash our feet, we must NOT FORM the intention of taking our stand on anything..EXCEPT according to the Command of Allahu Subhanahu Wa Ta'ala.