An Indian court's decision on Tuesday to ban Islamic instant divorces highlighted a controversial practice that is disputed in Muslim countries and already banned in some.
The instant divorce or "triple talaq" -- when a man says to his wife three times in succession "You are divorced" -- was deemed by the Indian Supreme Court to violate the constitution.
The historic practice has been controversial even among clerics, although the majority of classic Sunni jurisprudents have disapprovingly endorsed it as a less than ideal way of ending a marriage that runs counter to the spirit of scriptures.
Ideally, in classic Sunni law, a divorce takes place when a husband utters the equivalent of "You are divorced" three times over a period of months, usually three menstrual cycles.
Such a prolonged process would prevent impulsive divorces.
While Islamic law gives a man the unilateral right in general to divorce his wife, jurists cite a saying by the Prophet Mohammed conveying the gravity of ending a marriage.
"God has not created anything on earth he likes more than freeing a slave, nor has he created anything on earth he despises more than divorce," Mohammed is reported to have said.
However, such expressions of disapproval were meant to make husbands think twice -- or three times, in fact -- ahead of a unilateral divorce, rather than to suggest they are invalid.
Several Muslim countries have sought to restrict the "instant divorce" to varying degrees.
Some adopted what is known as "the sunna divorce", the procedure suggested in the Koran and laid out in prophetic traditions.
The countries with the four largest Muslim populations -- India, Pakistan, Bangladesh and Indonesia -- have all restricted instant divorces.
In Afghanistan, the civil code says pronouncement of divorce must be repeated three times with a large gap in between each. But that is ignored in rural areas of the country.
Jordan also does not recognise instant divorces. Couples are first required to go to court, which attempts to resolve their dispute.
In Egypt, where President Abdel Fattah al-Sisi sparked a dispute with the clergy after demanding an end to verbal divorces, the law says that the phrase "I divorce you thrice" counts only as one out of the three pronouncements needed to invalidate a marriage, which must then be notarised.
Under Syrian law, the question may come down to which of the four major schools of Sunni jurisprudence is followed by the couple in question.
Indonesia, the most populous Muslim country, banned men from unliterally ending marriages and requires that divorces be heard in court.
In Pakistan, the law requires couples to follow the pronouncement of a divorce with a three-month attempt at reconciliation.
In Nigeria, divorce is rampant in the Muslim north, in part due to recognition of the "instant divorce".
Other countries, including Saudi Arabia, allow the practice, although one of the most influential scholars of the Salafism school practised in the Gulf kingdom famously opposed it.
The 13th Century jurist Ibn Taymiyah, commonly seen as the godfather of Salafism, provoked outrage among the clergy of his era for insisting that the "triple talaq" counted only as one of the three required expressions of divorce.
His stance helped land him in prison in Damascus.
But centuries later, some governments have adopted the once controversial view in an attempt to restrict spur of the moment marital splits.