In Book Three, Section 6 of Jalaluddin Rumi's Masnavi, God instructs Moses to pray with a mouth that has not sinned. When Moses admits he lacks such a mouth, God explains that he should call upon Him through the mouths of others, as one cannot commit sins using another's mouth. Alternatively, Rumi explains that reciting God's pure name itself purifies the seeker's mouth, causing all spiritual pollution and grief to flee. This concept highlights the Sufi teachings on humility, collective prayer, and the transformative, purifying power of dhikr (remembrance).