it was arabia's custom at the time for the pious and thoughtful to devote a period of each year to a retreat of worship, asceticism, and prayer. they would seek an empty place far away from their people where they could concentrate on their prayers and genuinely seek a new level of seriousness, wisdom, and ethical goodness through meditation. this practice was called tahannuth or tahannuf. therein muhammad found the best means of satisfying his will to thinking and meditating. in its solitude he could find a measure of spiritual detachment and peace that would enable his consciousness to screen the whole universe for inspiration and to pursue his thought where it might lead. at the head of mount hira', two miles north of makkah, muhammad discovered a cave whose perfect silence and total separation from makkah made of it a perfect place for retreat. in that cave muhammad used to spend the whole month of ramadan. he would satisfy himself with the least provisions, carried to him from time to time by a servant, while devoting himself uninterruptedly to his spiritual pursuits in peace, solitude and tranquility. his devotion often caused him to forget himself, to forget his food, and, indeed, to forget the whole world around him. at these moments the very world and existence must have appeared to him like a dream. through his mind he would turn the pages of all that he had heard and learned, and his search could only whet his appetite for the truth.