This prayer was approved and enriched with an indulgence of five hundred days by Pope Pius X at all audience held on August, 1908, and was included in the official edition of approved indulgenced prayers (1950).
Raccolta number 389, 500 days Indulgence, Pope Saint Pius X audience, August 15, 1908.
QUOTE Why would the Blessed Virgin Mary appearing to a Native American of the recently conquered Aztec empire, and speaking to him in the native Nahuatl language, call herself “of Guadalupe”, a Spanish name? Did she want to be called "de Guadalupe" because of the statue of Our Lady of Guadalupe in Estremadura, Spain?In all apparitions of the Blessed Virgin Mary she identified herself as the Virgin Mary and phrases like Mother of God or another of Her Titles, and was later usually known by the name of the place or region where she appeared (Lourdes, Fatima).
So why should Mary, when appearing to a Native American in recently invaded Mesoamerica and speaking in the local language, want to be named with the Spanish name of Guadalupe?Was she referring to the miraculous statue of Our Lady of Guadalupe, that was given by Pope Gregory the Great to the Bishop of Seville, Spain, was lost for 600 years and was found in 1326 by a cowherd named Gil Cordero guided by an apparition of Our Lady? This statue was named Guadalupe for the village located near the place of discovery.The origin of the name Guadalupe has always been a matter of controversy. It is nevertheless believed that the name came about because of the translation from Nahuatl to Spanish of the words used by the Virgin during the apparition to Juan Bernardino, the ailing uncle of Juan Diego.
Some believe that Our Lady used the Aztec Nahuatl word of coatlaxopeuh which is pronounced "quatlasupe" and sounds remarkably like the Spanish word Guadalupe. Coa meaning serpent, tla being the noun ending which can be interpreted as "the", while xopeuh means to crush or stamp out. So Our Lady must have called herself the one "who crushes the serpent." UNQUOTE