The Kuzari writes: "For a chasid, the time of tefillah is the main time, whilst the other hours represent the preparations that lead to this important time (eating, learning Torah and everything else are like preparations for his tefillos). Those three times of daily prayer are the fruit of his day and night. He looks forward to this time because while it lasts he resembles the spiritual beings, and is removed from merely physical existence.
"This order of times of tefillah represent the needs of the soul. Prayer is for his soul what nourishment is for his body.
"One prayer lasts until the time of the next, just as the strength derived from the morning meal lasts until supper. The further his soul is removed from the time of prayer, the more it is darkened by coming in contact with worldly matters. This is even more so if necessity brings him into the company of youths, women, or wicked people; when one hears unbecoming and soul-darkening words and songs which sully the purity of the soul because these are things that are an attraction for his soul which he is unable to overpower. During prayer he purges his soul from all that passed over it, and prepares it for the future."
