Benedict did not definitively declare the Shroud that of Jesus Christ, but said it "wrapped the remains of a crucified man in full correspondence with what the Gospel tells us of Jesus."
In a meditation delivered after praying for four minutes before the Shroud, the pope said the relic should be seen as a photographic document of the "darkest mystery of faith" - that of Christ's crucifixion and resurrection.
The 14-foot-long, 3.5-foot-wide (4.3-meter-long, 1 meter-wide) cloth has gone on public display for the first time since the 2000 Millennium celebrations and a subsequent 2002 restoration. Kept in a bulletproof, climate-controlled case in Turin's cathedral, it has drawn nearly 2 million reservations from pilgrims and tourists eager to spend three to five minutes viewing it.
At the start of a Mass, Turin archbishop Cardinal Severino Poletto welcomed Benedict to join those who have silently prayed before the sepia-toned cloth, "this sacred linen that speaks in an impressive way of the Passion of Christ."
The Shroud bears the figure of a crucified man, complete with blood seeping from his hands and feet, and believers say Christ's image was recorded on the linen's fibers at the time of his resurrection.
Benedict focused in his meditation on the message that the blood stains conveyed, saying the Shroud was an icon written in the blood of a man who was "whipped, crowned with thorns, crucified and injured."
"Each trace of blood speaks of love and life," Benedict said.
Benedict's visit to the holy relic is a bit of a respite from meetings with bishops to discuss resignations from inside their ranks over sex abuse by priests of children and the bishops' failure to report it to civil authorities. In the past week, Benedict met with German bishops to discuss one high-profile resignation and he has another such meeting planned Monday with Belgian bishops.
In between, he met with five Vatican investigators who reported on an eight-month probe into the Legionaries of Christ; the Vatican announced Saturday that Benedict would appoint a personal delegate to lead the discredited order and reform it after revelations that its founder sexually abused seminarians and fathered at least one child.
While the visit to Turin is a break of sorts, it's not without its own controversies: The Vatican has tiptoed around the issue of just what the Shroud of Turin is, calling it a powerful symbol of Christ's suffering while making no claim to its authenticity.
A Vatican researcher said late last year that faint writing on the linen, which she studied through computer-enhanced images, proves the cloth was used to wrap Jesus' body after his crucifixion.
But experts stand by carbon-dating of scraps of the cloth that determine the linen was made in the 13th or 14th century in a kind of medieval forgery. That testing didn't explain how the image on the Shroud - of a man with wounds similar to those suffered by Christ - was formed.
However, some have suggested the dating results might have been skewed by contamination and called for a larger sample to be analyzed.
When Pope John Paul II visited the Shroud during a 1998 public display, he said its mystery forces questions about faith and science and whether it really was Christ's burial shroud. But he said the church had "no specific competence to pronounce on these questions" and urged continuous study.
Monsignor Giuseppe Ghiberti, president of the Turin archdiocese's commission on the Shroud, has said the Vatican, which owns the cloth, might consider a new round of scientific tests after the public display ends May 23.
During the 2002 renovations, cloth patches applied by French nuns in the 16th century to repair the Shroud after a fire were removed and fold marks and creases were smoothed out. The cloth is now kept flat rather than rolled out on a spool, to prevent creases from reappearing.
French crusader Robert of Clari mentioned seeing the cloth in 1203 in Constantinople at the imperial palace, but the first actual records trace it only to Lirey in France in 1354.
It was bequeathed to the pope by former King Umberto II of Italy, a member of the House of Savoy, upon his death in 1983.
