The solution is to "get rid of this bomb" by marrying your daughters off as soon as you can, he explains.
His customer, Hannane, replies firmly that Islam does not advocate child marriage and that women can also play an important role outside the home.
Hannane is one of a new generation of female religious leaders, known as morchidat -- part of a quiet social revolution in the North African country.
Their groundbreaking work is the subject of a British film, "Casablanca Calling", which will be showcased on Tuesday night at an international conference on child marriage in Morocco's famous port city.
The morchidat were introduced in 2006, partly in an attempt to counter Islamist radicalism following suicide bombings that rocked Casablanca in 2003.
The hope is that these female spiritual leaders can both encourage a more tolerant Islam and improve the position of girls and women in Moroccan society."
Read article by Emma Batha from Thomson Reuters Foundation.