Talaq types can be classified into "talaq al-sunnah", which is thought to be in accordance with Muhammad's teachings, and "talaq al-bid'ah", which are viewed as a bid'ah (innovation) deviations from it. "Talaq al-sunnah" is further subdivided into "talaq al-ahsan", which is the least disapproved form of talaq, and "talaq al-hasan". The "ahsan" talaq involves a single revocable pronouncement of divorce and sexual abstinence during the waiting period. The "hasan" divorce involves three pronouncements made during the wife's state of ritual purity with menstrual periods intervening between them, and no intercourse having taken place during that time.