ROME --Former Pope Benedict XVI, who shocked the world by resigning in February, has reportedly revealed that God told him to do it during a "mystical experience." The first pontiff to step down in six centuries, Benedict said, "God told me to," when asked about his decision to dedicate himself to a life of prayer instead. The 86-year-old pope emeritus said he had not witnessed a vision of God but had undergone a months-long "mystical experience" during which God gave him the "absolute desire" to forge a deeper relationship with him. Benedict also said that the more he witnessed the "charisma" of his extremely popular successor, Pope Francis, the more he understood how his stepping aside was the "will of God." The former pontiff's comments were reported by the Catholic news agency Zenit, which did not disclose to whom Benedict made the remarks. But the report was backed by a senior Vatican source. "The report seems credible -- it accurately explains the spiritual process that brought Benedict to resign," the source told The Times. When announcing his resignation to cardinals on Feb. 11, Benedict had focused on his ill health, stating his strength "has deteriorated in me to the extent that I have had to recognize my incapacity to adequately fulfill the ministry entrusted to me." Observers have also speculated that Benedict was demoralized both by the leaking of his personal correspondence by his butler and by the lobbying of an alleged group of gay clergy within the Vatican. Zenit reported that in the last six months, Benedict has received few visitors at the secluded house he now occupies in the Vatican's gardens. "During these meetings, the ex-pontiff does not comment, does not reveal secrets, does not make statements that could be understood as 'the words of the other pope,' but is as reserved as he has always been," Zenit said. Francis last month joked about having two popes under one roof, telling reporters: "The last time there were two or three popes, they didn't talk among themselves and they fought over who was the true pope!" But having Benedict living in the Vatican, he added, "is like having a grandfather -- a wise grandfather -- living at home."