Pope Leo honoured Spain’s centuries-old tradition of religious devotion on Sunday as a “school of faith” for today, as he presided over a Mass before more than a million people that highlighted one of the most iconic expressions of Spanish popular piety: a procession over flower-petal carpets.The crowd cheered and shouted “This is the youth of the pope!” as Leo arrived for the Mass at a central Madrid plaza. He looped around the plaza and surrounding streets in his Popemobile before a crowd packed several rows deep with people eager to witness the first papal trip to Spain since 2011, when Pope Benedict visited for World Youth Day.Sunday’s Mass fell on the Catholic Corpus Domini feast day, which often features processions of faithful through towns and cities led by a priest carrying the Eucharist. In Spain, as in other predominantly Catholic countries, the processions often feature elaborate floral carpets arranged along the route.Leo, who arrived in Spain on Saturday at the start of his weeklong visit, has been keen to highlight the long tradition of Catholic devotion here to encourage especially young generations to find their faith. It is a tall order in a once-staunchly Catholic country where religious observance has largely been on the wane.In his homily on Sunday, Leo honoured Spain’s tradition of the Corpus Domini processions, saying the floral carpets express the “spiritual sentiments of this country” through “altars erected in the streets”.“This is not an exhibition, a remnant of folklore or a simple display of beauty,” he said. “It is a profession of faith in the presence of the risen Lord, who is alive and continues to walk among us.”