Celebrating the traditional Holy Thursday foot-washing ritual at a Roman men’s prison, Pope Francis said that if, throughout history, kings, emperors and world leaders had followed Jesus in his attitude to serve those they led, “many wars would not have happened.”

“Those who lead, must serve,” Francis said during his homily in the Holy Thursday ceremony, which this year took place in Rome’s Regina Coeli prison.

Francis also used the occasion of the prison visit to reiterate his opposition to the death penalty and life imprisonment, even without using those phrases directly.

“There is no just punishment — just! — that doesn’t leave open hope. A punishment that’s not open to hope is not Christian, it’s not human!” he said in impromptu farewell remarks.

On the subject of leadership as service, Francis said that in Jesus’ times, roads were made of dirt, so slaves would wash the feet of those arriving to a home.

Washing feet, Francis said, “was the work of a slave, but it was a service. A service performed by slaves. And Jesus wanted to perform this service to give us an example of how we have to serve one another.”

Those who lead, those who are bosses, the pontiff insisted, must learn how to serve, because it’s a key element of leadership.

“Let’s think throughout history. If so many kings, emperors, heads of state, had understood this commandment of Jesus, instead of giving orders, being cruel, had behaved like this, how many wars would not have happened,” Francis said.

“There are people who don’t facilitate [real service], who are superfluous, hateful, who wish us evil,” Francis said. “These, we must serve even more. There are people who suffer, who are discarded from society, at least for a period of time, and Jesus goes there, to tell them ‘You are important for me.’ And Jesus comes to serve us.”

Jesus, the pontiff continued, “risks himself for each one of us.” His name, Francis said, is “Jesus, not Pontius Pilate. He doesn’t know how to wash his hands. He only knows how to risk [himself for us.]”

Christ “never abandons us. He never tires of forgiving us. He loves us so much,” he said, delivering his homily off the cuff.

Francis’s words came as he was celebrating the Last Supper Mass in Regina Coeli, Rome’s best-known men’s prison. It was originally a Carmelite convent, and was used during the fascist era to house political prisoners. Today, it can house up to 900 inmates.

Among other things, it holds the record of being the first prison in modern times to be visited by a pope: John XXIII did so in 1958, during his first months as the successor of Peter. Since then, it was also visited by Pope Paul VI in 1964 and by John Paul II in 2000.

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The visit, which was strictly private, wasn’t televised, and at the time this article was published, there was no footage of Francis performing the foot-washing ritual.

However, ahead of the visit, the Vatican announced that among the 12 who would participate in the ritual were four Italians, two from the Philippines, two from Morocco, one from Moldova, one from Colombia, one from Nigeria and one from Sierra Leone. Eight of them are Catholic, two Muslims, one Orthodox and a Buddhist.

Upon arriving at the prison, Francis encountered the inmates who were in the infirmary.

The Argentine pontiff has a long history of visiting those in prison, considered one of the works of mercy. Since being elected to the pontificate, he’s continued making regular calls to a prison in Argentina.

Explaining the reason behind his regular visits to jails, that also take place during many of his apostolic visits outside of Italy, Francis has said: “I think to myself, ‘I, too, could be here.’ That is, none of us can be sure that we would never commit a crime, something for which we’d be put in prison.”

This is the fourth time the pope has celebrated the Holy Thursday Mass at a prison, picking up on a tradition he developed when he was archbishop of Buenos Aires.

During the first year of his pontificate, he headed this ceremony at the juvenile detention center “Casal del Marmo.” In 2014, Francis held the Holy Thursday Mass at the Don Gnocchi center for the disabled.

In 2015 he once again went to a prison on the outskirts of Rome, Rebibbia, where he washed the feet of 12 inmates, men and women, from Nigeria, Congo, Ecuador, Brazil, and Italy – as well as one toddler.

The following year, he visited a center for asylum seekers in Castelnuovo di Porto, where he washed the feet of refugees. Among them were Muslims, Hindus, and Coptic Orthodox Christians.

Last year, the pontiff performed the ritual at the Paliano, a maximum security prison located south of Rome used to house mafia turncoats.

The pontiff opened the most solemn period of the Church’s liturgical calendar by celebrating Palm Sunday Mass in St. Peter’s Square, where he both delivered a sort of media criticism suggesting Jesus was the original target of false public “spin,” and also urged young people not to “keep quiet” about their faith and their dreams.

Before the in Coena Domini Mass, Francis began Thursday celebrating the Chrism Mass in St. Peter’s Basilica, delivering his annual message to priests from around the world.

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On Friday, he will participate in the liturgy marking the Lord’s Passion in St. Peter’s Basilica. This is one of the few occasions in which the pope does not deliver a homily. Later in the day he’ll lead the torch-lit Way of the Cross at Rome’s Colosseum, which this year was written by a group of high school students.

On Saturday night he’ll lead the Easter vigil at the basilica, and on Sunday, out in St. Peter’s Square, he’ll lead the Easter Mass and deliver the Urbi et Orbi blessing, to the city of Rome and to the world.