In 1251, Mary appeared as Our Lady of Mount Carmel to Saint Simone Stock, General of the Order of Carmelites, holding in her hand a scapular. She directed him to found a confraternity whose members should wear it and consecrate themselves to her service. Ever since then, the title “Our Lady of Mount Carmel” and the scapular have been inseparably linked.

It is also a tradition among the Carmelites that when Elijah the prophet (of Mount Carmel) threw his cloak over Elisha thus imparting his spirit to him, it was a prefiguration of Mary clothing her children with the brown scapular. A prophecy attributed to Saint Dominic further underlines this importance,” one day through the rosary and the scapular, she (Our Lady) will save the world.”
 

A Divine Theme - at Lourdes, France, we can begin to see a divine theme being developed. The Blessed Virgin’s last appearance at Lourdes was on July 16, 1858, feast of Our Lady of Mount Carmel. During the final apparition at Fatima, October 13, 1917 when the “miracle of the sun” occurred, Our Lady first appeared as she had been appearing to the three shepherd children with her sorrowful heart exposed. And then she appeared as Our Lady of Mount Carmel with “something hanging from her right hand.” We can safely assume that the “something” was the scapular.
 

Read more about the brown scapular here...