ROME — In a ceremony that began with a chorus of crying babies battling for vocal supremacy with the famed Sistine Chapel choir’s elegant Gregorian chant, Pope Francis baptized 26 infants on Sunday, all children of Vatican personnel.

“Don’t forget that in the end, the most important inheritance you can give your children is their faith,” Francis said in his impromptu homily, perhaps one of the shortest in modern papal history and certainly in this papacy: A grand total of 150 seconds, give or take.

“Today, on the feast of the Baptism of the Lord, you, parents, bring your children for them to receive baptism,” he said, saying they do so to pass on the faith to the next generation.

Parents, he said, want for their children “that which you asked for at the beginning [of the ceremony], when I questioned you: the faith.”

Francis then told the parents to raise their children in the faith, making sure it’s not lost, but instead grows along with the children.

The papal baptism is an annual ceremony, always held the first Sunday after Jan. 6, the Epiphany, marking the visit of the Magi to the infant Jesus. In Catholic tradition, Epiphany marks the end of the Christmas season.

At the end of his homily, Francis reiterated his openness to breastfeeding, which he has told mothers several times before: “If your child cries because he [or she] is hungry, feed him here, with complete freedom.”

Respecting the layout of the Sistine Chapel, where the baptism Mass is traditionally held, the pope celebrated in the ad orientem fashion, meaning “to the east” — his back to the congregation.

It’s the posture generally associated with the older Latin Mass, although Francis on Sunday used the rite developed after the Second Vatican Council (1962-65).

The ceremony began with Francis tracing the Sign of the Cross on the foreheads of the 26 infants, 13 girls and 13 boys, all born in the past year.

During the baptism rite, Francis pronounced each baby’s name and poured water from a golden shell-shaped cup onto their foreheads, welcoming them into the faith. As is often the case, some squirmed in their parents’ arms while others slept peacefully.

Later on Sunday, during his noontime Angelus address, Francis reflected on the importance of baptism. In an extemporaneous flourish, he asked the crowd in St. Peter’s Square if they knew the date of their own baptism.

“This is your homework for the week,” he said. “Go and find out the date of your baptism,” suggesting Catholics should mark the date as an important moment in a life of faith.

While Sunday’s meeting with Vatican workers and their babies had an intimate feel, on Monday Pope Francis will lead an event with a much more formal atmosphere: His annual address to the diplomatic corps accredited to the Vatican, which is generally considered his most important foreign policy speech of the year.