While anger over the brutal attacks was still raw among the crowd, some say it's important to avoid moves of revenge.
"Every human life is sacred, and most people lift up the value that if you save a life you save all human beings," Rabbi Sarah Hronsky said. "We stay in that space of hope that brutality shall not continue to reign, and that we will respect and love one another."
At Los Angeles City Hall, council members pledged support for Israel.
Meantime, the L.A. chapter of the Council on American-Islamic Relations, a Muslim civil liberties organization, is condemning the killing of Israeli civilians, but the group says the attacks were the result of decades of oppression by Israel.
"Seventy-five years of this possession of the Palestinian people, occupation by the Israeli government, siege for 15 years against the Palestinian people, daily abuses and harassment and dehumanization on a daily basis," CAIR executive director Hussam Ayloush said. "Palestinians are dying."
At least 900 people have died and 2,600 others have been injured in Israel after the militant group Hamas launched an unprecedented incursion from air, land and sea on Saturday, Israeli authorities said.
Hamas fired thousands of rockets toward Israel and an estimated 1,000 fighters crossed into the country from the neighboring Gaza Strip. Israeli officials said at least 100 civilians and soldiers have been taken hostage.
ABC News contributed to this report.