(Arabic: “reminding oneself,” or “mention”), ritual prayer or litany practiced by Muslim mystics (Ṣūfīs) for the purpose of glorifying God and achieving spiritual perfection. Based on the Qurʾānic injunctions “Remind thyself 【udhkur】 of thy Lord when thou forgettest” (18:24) and “O ye who believe! Remember 【udhkurū】 Allāh with much remembrance” (33:41), the dhikr is essentially a “remembering” of God by the frequent repetition of his names. Originally a simple recitation of the Qurʾān and various religious writings among ascetics and mystics, the dhikr gradually became a formula (e.g., lā ilāha illa ʾllāh, “there is no god but God”; Allāhu akbar, “God is greatest”; al-ḥamdu līʾllāh, “praise be to God”; astaghfiru ʾllāh, “I ask God's forgiveness”), repeated aloud or softly, accompanied by prescribed posture and breathing. As the Ṣūfī brotherhoods (ṭarīqahs) were established, each adopted a particular dhikr, to be recited in solitude (e.g., following each of the five obligatory daily prayers) or as a community. The dhikr, like fikr (meditation), is a method the Ṣūfī may use in his striving to achieve oneness with God.