Posted on 06/28/2012 by __socrates

NIYAH. نية
A vow; intention; purpose. A term used for the vow or declaration of the intention to perform prayers. ‘I have purposed to offer up to God only with a sincere heart this morning (or, as the case may be), with my face Qiblah-wards two (or, as the case, may be) rak’ah prayers farz (sunnah, nafl or witr) It, is also used by a Muslim about to perform the pilgrimage or the month’s fast. The formula is necessary to render an act of devotion acceptable. [PRAYER.]

Based on Hughes, Dictionary of Islam