The method of learning dhikr [is] for the disciple to sit before his Sufi master and then they start breathing rhythmically together. The disciple follows the master and starts saying the shahadah as he exhales: "La ilaha illa 'llah." This becomes a total renunciation of everything except God. In this process the disciple concentrates on what is happening. He thinks: "I want nothing, I love nothing, I seek nothing but God." The exhaling breath turns everything out, and then he breathes in love, desire and total concentration on God. The aim is for the whole person to be completely centered on God.

— Gray Henry, Rob Baker in Merton and Sufism