Breath is termed by Sufis Kasif and Latif; Kasif means "dense" and Latif means "fine."

• Dense breath is that which is noisy and labored, which strains the nerves and the lungs. The exercises of dense breath are useful for developing the muscles and for gaining control over the nerves; they are helpful also to the lungs and useful to the physical health.
• But in spiritual development unless the breath be made fine it cannot penetrate through the important centers in the body and it cannot reach far enough into the innermost parts of one's life.