First of all, a Muslim should take the words of divorce seriously. Muslim scholars differ on whether pronouncing divorce three times on one occasion is counted as one or three divorces. According to scholars such as Ibn Taymiyyah and Ibn Al-Qayyim, triple divorces that are pronounced concurrently are considered only as a single divorce.
Sheikh Muhammad Nur Abdullah, president of the ISNA (Islamic Society of North America) and member of the Fiqh Council of North America, states: In order to understand the difference, we should recognize that there are two types of divorce in Islam: One is called sunni, which means it is done according to what has been stipulated in the Sunnah; the other kind is called bid`i, which means it has been done in a different way contrary to the Sunnah of Prophet Muhammad (peace and blessings of Allah be upon him).
A sunni divorce means that a husband divorces his wife once, at a time she is not menstruating or at a time of purity in which no sexual intercourse happened between them. A bid`i divorce means the husband divorces his wife in a situation opposite to what has been stated in the sunni divorce, such as during menstruation.
Divorcing a wife thrice in one sitting is considered a bid`i divorce. That is why Muslim scholars have held different views on whether such a divorce counts or not, and if it does count, whether it counts as revocable or irrevocable divorce. The majority of scholars say that a triple divorce counts as once, because it is reported that a man came to the Prophet and told him that he had divorced his wife three times. The Prophet told him that one of them has been considered and the rest have been disregarded.