TO travel through the seething metropolis that is Cairo during the holy month of Ramadan is to experience the quiet power of Islam.
In this overwhelming crossroads of human interaction, the impact of Ramadan is all the more evident - the quiet interludes more poignant, and the empty Friday streets invite a meditation.
It is simultaneously a festival both somber and joyous. But its manifestations are ubiquitous and its message inescapable.
The limitations Ramadan places on indulgence of the senses contains a clear spiritual lesson: that the true nature of something is only revealed when we can experience its end.
The dawn-to-dusk daily fast - beginning with the sighting of the new moon in the ninth month of the Islamic calendar and ending with the sighting of the next moon 30 days later - is an act of purification, sacrifice, and renewal.
At a moral level, it gives people a direct experience of the suffering of the poor and hungry. It is also a time of giving.
``You naturally identify with the poor because you actually feel what it is like to be hungry and to have no possessions,'' says Mohammed Ashraf Abdel-Hakim, a student at the University of Cairo.
But above all, it is a time of praying and reading the Koran, Islam's holy book.
There are additional prayers to add to the five daily Muslim prayers, and Friday mosque attendance is higher than usual.
``During the year, I do not often find the time to pray between my studies and a busy life,'' Mr. Hakim says.
``But during Rama- dan, I make up for it. I pray every day, and I give food to the poor and the hungry,'' Hakim says. ``If you don't respect the month of Ramadan, you cannot be a good Muslim.''
Hakim looks forward to the evening meal, known as breakfast, which is taken after sunset in a festive atmosphere with family and friends.
In the local souk (market), the streets come alive with special Ramadan lights, flags, and banners that festoon the streets.
During the day, the people are subdued, and the food stalls are quiet, save for the sweet and pastry stalls that work overtime to prepare the kunefa (pancakes) that are filled with an assortment of white cheeses, nuts, and honey to round off the breakfast meal.
Or they are busy making the string-like atayef (a kind of shredded pastry) that is used to make a variety of sweets.
The light breakfast is often followed by a heavier meal before midnight.
Hakim concedes having a soft spot for the optional early morning meal of suhoor, which usually consists of foule - a delicious bean stew eaten with pita bread and chili.
The meal follows a 3:30 a.m. wake-up call from an elderly member of the community who walks the streets beating a drum and shouting. This allows the meal to be taken before the first ray of light is seen.
The reverence that accompanies the almost universal observance of Ramadan is humbling - and thought-provoking.
Is this part of the religious revival across the Muslim world that has spawned a dramatic growth in mosque attendance and outward manifestations of Islam such as the veils women wear?
``There is no doubt that the observance of Ramadan has become more thorough and more public in the last few years,'' says noted Egyptian columnist Mohammed Sid Ahmed.
``In the days of [former President Gamal Abdel] Nasser there was less strict observance,'' Mr. Ahmed says. ``People would smoke in the street. Today no one would dare to smoke, and restaurants are instructed not to sell [alcoholic] drinks even to foreigners.''
He says the observance of Ramadan is a good barometer of the state of mind of Islam. ``The observance we see today highlights this phenomenon of Islam and the way it is taking over. It is a manifestion of a religious revival that also has a militant political aspect.
``Most of the people involved in the religious revival do not perceive themselves as being part of the political side, but the religious revival creates an atmosphere in which the political elements can flourish,'' Ahmed says.