Delayed auditory feedback (DAF), in which stutterers hear an echo of their own speech sounds, has also been effective in treating stuttering.
Most of his matchless odes were composed in honour of the Maulawi dervishes, and even his opus magnum, the Mathnawi (Mesnevi), or, as it is usually called, The Spiritual Mathnawi (mathnawi-i-ma`nawi), in six books or daf tars, with 30,000 to 40,000 double-rhymed verses, can be traced to the same source.
After the sun is down the vast assemblage breaks up, and a rush (technically ifada, daf`,nafr is made in the utmost confusion to Mozdalifa, where the night prayer is said and the night spent.
The Welsh form of the name, Caerdydd (pronounced Caerdeeth, with the accent on the second syllable) suggests that the name means "the fort of (Aulus ?) Didius," rather than Caer Daf ("the fortress on the Taff"), which is nowhere found (except in Leland), though Caer Dyv once existed as a variant.