Pope Francis was photographed at the hospital for the first time since he was admitted last month for double pneumonia.

The 88-year-old pope concelebrated the Holy Mass Sunday morning in the chapel of Rome’s Gemelli Hospital, the Vatican stated, sharing the first image of the pope since his hospitalization.

A Vatican official also confirmed on Sunday that his condition remains stable.

“Throughout the day, he continued his therapy, including motor and respiratory physiotherapy. He has particularly benefited from motor physiotherapy,” the official said in a briefing. “During the day, he was able to work a little, and in the coming days we will see the results of his work.”

Last week, Francis surpassed four weeks of hospitalization just after marking the 12th anniversary of his election as the 266th pope.

Earlier this month, Francis participated virtually in the Vatican’s weeklong spiritual retreat, an annual gathering that kicks off the Catholic Church’s solemn Lenten season leading to Easter. He joined via videoconference, where he was able to see and hear the Rev. Roberto Pasolini, preacher of the papal household, but the priests, bishops and cardinals in the Vatican auditorium couldn’t see or hear him.

Francis, who had part of one lung removed when he was young, was admitted on Feb. 14 as a result of a complex respiratory infection. What was initially a bad case of bronchitis progressed into a respiratory tract infection and double pneumonia that threatened his life and raised concerns about the future of his papacy.

But the pope has since been declared safe from the imminent danger of death, and he has been making gradual progress in his recovery. His latest medical bulletin noted that a chest X-ray confirmed improvements.

Still, doctors have remained cautious about his overall fragility, saying that he needs to remain hospitalized for an unspecified number of days.