He received the Carmelite Scapular from the Blessed Virgin.
Saint Simon Stock is one of the main characters in the history of the Order of Carmel; the structural change of the Order is due to him, leaving the original hermitism and being part of the mendicant orders or apostleship.
Saint Simon from England, sixth General of the Order, who prayed every day to glorious Mother of God to give any sign of her protection to the Order of Carmelites, who enjoyed the singular title of the Virgin, saying with all the fervour of his soul these words:
Flos Carmeli
Vitis Florigera Splendor coeli Virgo puerpera Singularis y singular Mater mitis Sed viri nescia Carmelitis Sto. Propitia Stella maris |
Flower of Carmel
florid vineyard splendor of Heaven Fecund Virgin Oh tender Mother! intact of man to carmelites protect your name (give privileges) Starfish of sea. |
The 16 of July of 1251, the Blessed Virgin Mary, accompanied by a multitude of angels, she appeared to Saint Simon Stock, General of Carmelites, with the Scapular of the Order in her hands, and told him: "You and all the Carmelites will have the privilege, that who dies with it won´t undergo the eternal fire"; it means, who dies with it, will be saved.
This narration can be found in saints calendar since endings of XIV century, no doubt that is taken from older codices. In the same XIII century William of Sandwich O.C. mentions in his "Chronicle", the appearance of the Virgin to Saint Simon Stock promising him the help of Pope.
Bibliography:
http://es.catholic.net/op/articulos/36062/simn-stock-santo.html
https://www.aciprensa.com/recursos/el-escapulario-de-la-virgen-del-carmen-1048/