Pope Emeritus Benedict XVI is in stable condition and was "able to rest well" Thursday night, the Vatican said Friday.

"He also participated in the celebration of Holy Mass in his room yesterday afternoon," the Holy See said. "At present, his condition is stable."

Pope Francis raised concern about Benedict XVI's health on Wednesday when he concluded the General Audience with an invitation for the faithful to pray for his 95-year-old predecessor who, he said, is ill.

Matteo Bruni, Director of the Holy See Press Office, said Thursday that Pope Francis "renews his invitation to pray for him [Benedict XVI] and to accompany him in these difficult hours."

The director of the Press Office said Francis on Wednesday visited the Pope Emeritus at the Mater Ecclesiae monastery after the General Audience. Benedict XVI has lived at the monastery inside the Vatican since announcing his resignation in February 2013.

According to NPR, Benedict became the first pope in 600 years to retire, and few had expected his retirement to last longer than his eight-year pontificate.

The diocese of Rome scheduled a special Mass in honor of Benedict for Friday at St. John Lateran, Benedict's former basilica in his capacity as the bishop of Rome, NPR reported.

When news broke of Benedict's declining health, questions were raised about the protocol surrounding his death and funeral, as it would be unprecedented to have a reigning pope preside over the funeral of a former pope.

Vatican experts told NPR it was likely that any funeral for Benedict XVI would resemble that of any retired bishop of Rome, with the caveat that official delegations would be present to honor the former head of state. Pilgrims from Benedict's homeland of Germany and beyond were also to be expected.

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