Vatican City • Pope Francis ushered in the most solemn period in the Catholic liturgical calendar by celebrating a Holy Thursday Mass and the ritual washing of the feet, made more poignant this year after the devastation of Paris’ Notre Dame Cathedral.

The Chrism Mass celebrates the unity of priests with their bishops. During Thursday’s service in St. Peter’s Basilica, Francis blessed the holy oils that will be used over the course of the year in the administration of sacraments.

In his homily, Francis stressed that when priests use the oil, they are distributing their vocation and heart to the people of God.

“We anoint by dirtying our hands in touching the wounds, the sins and the worries of the people,” he said. “We anoint by perfuming our hands in touching their faith, their hopes, their fidelity and the unconditional generosity of their self-giving.”

This year, the final days of Holy Week — which for Catholics commemorates Christ’s crucifixion, death and resurrection — have taken on particular resonance after the fire at Notre Dame, a symbol of French Catholicism.

Francis has offered his condolences repeatedly to the French faithful, and French President Emmanuel Macron said Thursday that during a call to Francis after the blaze, he had invited the pontiff to visit Paris. On Wednesday, Francis fielded a call from U.S. President Donald Trump offering the sympathy of the American people over the loss, the Vatican spokesman said.

Later Thursday, Francis travels outside Rome to Velletri, where he will celebrate the ritual foot-washing ceremony at a prison. Francis has frequently chosen to wash the feet of prisoners during the Holy Thursday ritual, which re-enacts Christ’s washing the feet of his disciples, in a bid to show his willingness to serve even those on the farthest margins of society.

On Friday, he presides over the Way of the Cross procession at Rome’s Colosseum reenacting Christ’s crucifixion, followed by the Easter Vigil and Easter Sunday in a flower-decked St. Peter’s Square.