Besides making ablutions it is necessary that the channels of the breath be kept clean, and for this, consideration is necessary about what one eats and drinks. Food that is raw and indigestible, and stale food, stale and decayed vegetables, rotten fruits, and meat that has been preserved for a long time, and all such things not only block the channels of the breath, but their influence on the breath makes it impure. Naturally when a person cannot digest food or when his lungs are not open and free the breath is not pure. The Sufi takes care in his life about what he should eat and what he should drink. Alcoholic drinks and drinks made from decayed fruits, naturally make the breath impure; even smoking tobacco has a bad effect on the breath. Those who observe the mystical rules carefully refrain from all flesh food, even from eggs. White meat is preferable to red meat, for red meat has particles which block the channels of the breath. This was the reason why the eating of pork was prohibited by the prophets of Beni Israel. No doubt to the pure all things are pure, but in order to become pure it is necessary to observe the rules of purity.