Barack Obama made his first formal appearance as US president on Wednesday at a traditional post-inauguration prayer service presided over by an ecumenical assembly of religious leaders that included three rabbis. Civil rights activist Rabbi David Saperstein, head of the Religious Action Center of Reform Judaism and a Washington power player, began his reading of Psalm 121 in Hebrew, then went on to recite in English, "I lift up my eyes to the mountains." Obama sat in the front row flanked by his wife, Michelle, and Vice President Joe Biden and his wife, Jill. The new president looked pensive throughout the 90-minute service, but flashed a broad grin and clapped when Protestant minister Sharon Watkins - the first woman to deliver the sermon at the national prayer service - addressed Michelle Obama as "Madame First Lady." Watkins appealed for generosity and "neighborly" relations among Americans and between the United States and the rest of the world. She cited a call by Muslim scholars for finding peace through a common "love of god and love of neighbor," and called on Obama to reason from the center and to draw on his moral "bedrock" in making hard decisions about international affairs and the economy. "In international hard times, our instinct is to fight, to pick up the sword, to seek out enemies, to build walls against each other, and why not? "They might just be out to get us. We have plenty of evidence to that fact, and someone has to stand watch," Watkins said. "Mr. President - tag, you're it." Secretary of State-designate Hillary Clinton sat at the end of the front row with former president Bill Clinton, who swayed and sang along with a gospel choir performing the spiritual "He's got the whole world in his hands." Rev. Samuel T. Lloyd III, the dean of the Washington National Cathedral, opened the service with a nod to Martin Luther King Jr., who delivered his last Sunday sermon - on "Remaining awake through a great revolution" - in the soaring stone building. Rabbi Jerome Epstein of the United Synagogue of Conservative Judaism, the association of North American Conservative congregations, and Modern Orthodox Rabbi Haskel Lookstein of Congregation Kehilath Jeshurun in New York both participated reading the responsive prayer for the nation. The Rabbinical Council of America issued a statement frowning on Lookstein's involvement because it contravenes Jewish law prohibiting participation in services held in churches. The organization's executive director, Rabbi Basil Herring, told The Jerusalem Post that the statement had nothing to do with Obama, but was simply a reiteration of principle. "That's as far as it goes," Herring said. Lookstein said he felt it was important to make an exception to make sure the Orthodox movement was represented along with the Conservative and Reform movements. "I felt these were special circumstances to support the new president of the United States," Lookstein told the Post. Dr. Ingrid Mattson, the president of the Islamic Society of North America, opened the prayer for the nation, which calls on both God and political leaders to "keep this nation under your care." Her participation stirred controversy because federal prosecutors in Texas have suggested in court documents that her organization - one of America's largest Muslim associations, which trains FBI agents and certifies Muslim chaplains for the military and prisons - had some connection to Hamas funding networks in the US. The society was never charged with any crime. Jewish leaders, Bush administration officials and Obama's inaugural committee dismissed the allegation and defended Mattson, who took over the group in 2006, as a respected religious leader with "a stellar reputation."