Sistani has made declarations in the past calling on Iraqis to respect state institutions and public order. He has not spoken directly on the violence involving Sadr's supporters, but he is expected to make a statement in the next few days.
"The Hawza (seminary) is unanimous on this," the aide said.
"We asked Moqtada (al-Sadr) to stop resorting to violence, occupying public buildings and other actions that make him an outlaw. He insists on staying on the same course that could destroy the nation."
He said Moqtada had refused to meet a tribal delegation and representatives of Bahr al-Uloum at the main mosque of Kufa, near the holy city of Najaf, where he is staging a sit-in with armed followers.
"The delegation met Moqtada's aides, who did not express interest in relying on wisdom and patience," the aide said.
A Shi'ite religious source said Sadr has moved from Kufa to Najaf's Imam Ali shrine, the holiest Shi'ite site in Iraq, and armed followers have closed off streets leading to the shrine.
and wrapped himself in Sistani's authority:
He also aligned himself with Iraq's most influential religious figure, Grand Ayatollah Ali al-Sistani. "I proclaim my solidarity with Ali Sistani, and he should know that I am his military wing in Iraq," he said.
Mr. Sadr, whose followers on Sunday began the most serious insurrection of the postinvasion period, said, "I will put the city with the golden dish between Ali Sistani's hands after liberation."
The golden dish refers to the golden shrines of Najaf, some of the holiest sites in Shia Islam. Najaf, south of Baghdad, is the home of Ayatollah Sistani, who is considered much more moderate than Mr. Sadr. On Sunday, Ayatollah Sistani issued a religious decree urging Iraq's Shiites to stay calm.