Vatican City — Pope Francis' highly anticipated encyclical letter on environmental issues is reportedly to be given the title "Laudato Sii," a quotation from a popular prayer of St. Francis of Assisi praising God for the creation of the different creatures and aspects of the Earth.

Translated in English either as "Be Praised" or "Praised Be," the title of the letter was first reported on Twitter mid Saturday by Spanish language journalist Mercedes De La Torre. She was attending an event honoring the Libreria Editrice Vaticana, the Vatican publishing house responsible for printing official documents.

The title has not been confirmed, but a photo posted by De La Torre shows the director of the publishing house, Salesian Fr. Giuseppe Costa, speaking at the event. De La Torre also said in a brief conversation that the encyclical is to be given an Italian subtitle: "Sulla cura della casa comune" (On the care of the common home).

According to Catholic News Service, Costa told reporters the encyclical will be released June 16. The Vatican press office neither confirmed nor denied the document title or release date, CNS reported.

Francis' upcoming encyclical has been widely anticipated around the world for what stance it might take on global climate change. An encyclical letter is generally considered one of the highest forms of teaching for a Catholic pope.

The phrase "Laudato Sii" reoccurs several times in St. Francis' Canticle of the Sun, a prayer that praises God first by thanking God for such creations as "Brother Fire" and "Sister Water."

Written around the year 1224, the prayer is also recognized as one of the first published works of literature in the Umbrian dialect of the then-developing Italian language as opposed to Latin.

"Be praised, my Lord, through all Your creatures, especially through my lord Brother Sun," St. Francis wrote in the third stanza of the prayer. He then continued, expressing praise to God for "Sister Moon," "Brothers Wind and Air," "Sister Water," "Brother Fire, and "Mother Earth."

[Joshua J. McElwee is NCR Vatican correspondent. His email address is jmcelwee@ncronline.org. Follow him on Twitter: @joshjmac.]

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