Alleluia. Levita Laurentius bonum opus operatus est, qui per signum crucis cæcos illuminavit. Alleluia.

Alleluia. The Levite Lawrence wrought a good work, who by the sign of the Cross, gave sight to the blind.

Alleluia.

St. Lawrence, deacon of Pope Sixtus II, was sentenced to death on 10 August, 258. His burial on the Via Tiburtina is attested by the Depositio Martyrum of 354, and the feast of St. Lawrence has been ranked highest in the Roman sanctoral cycle since its origins. The popularity of the deacon who, according to his martyrdom, was burned alive over a grill after distributing the goods of the Church to the poor, spread rapidly: according to St. Leo, Rome became "as famous thanks to St. Lawrence as Jerusalem was glorified by Stephen''.

After the beheading of Pope Sixtus II, Lawrence was arrested, and summoned by the Prefect of Rome, Cornelius Secularis, to hand over the Church's treasures to the Emperor. When he asked for time to make an inventory and was given three days, St. Lawrence immediately set about distributing to the priests and the poor the money and treasures of the Church. On the third day, Lawrence presented him with all the poor of the Church of Rome. "Here," he said, "are the treasures of the Church; by our lives and celebrations we gather great riches from heaven." Furious, the Emperor ordered St. Lawrence to be tortured with reddened blades and whips. But nothing made him flinch. Stripped of his clothes and placed upon the glowing gridiron he refused to offer a sacrifice to the pagan gods and proclaimed: "I offer myself to God as a sacrifice because a spirit that has the regret of its sins is received by God with tenderness." St. Lawrence said he felt nothing. With faith and fortitude, he triumphed over the fire. Turning to the Emperor, he is said to have said, not without humour: "Behold, wretched man, this part is cooked, turn it over and eat it.”

In Spain, the Royal Site of San Lorenzo de El Escorial, a large architectural complex (monastery, palace, royal mausoleum and library) built during the reign of Philip II, has a plan of its square courtyards arranged in a chessboard pattern, reminiscent of the shape of a grill. 

The alleluiatic verse alludes to the miraculous healing of the blind man Crescention, operated on by St Lawrence. While the deacon of Rome was dispersing Church goods, there was a blind man named Crescentius who asked for healing by the laying on of hands. The holy deacon made the Sign of the Cross over him and the man began to see.

As for the alleluia chant, the melody is modelled on the alleluia, Laetabitur Justus. In the verse, we note that the emphasis is on bonum opus operatus est (has accomplished good work), an accent of fervour that underlines the magnificence of St. Lawrence and develops on the high notes of opus and operatus in the happiest way. On the word crucis, at the beginning of the second phrase, the melody unfolds in the same ardent atmosphere. In the manuscript tradition, this song had a longer text: et thesauros Ecclesiae dedit pauperibus (and gave the treasures of the Church to the poor) in reference to the action that earned him martyrdom.