This was the name given to certain Jewish groups and sects who, for centuries after the destruction of the Temple, continued to remain in deep, constant mourning, symbolizing the destruction of the Temple and the Land of Israel.
Currently, on certain days and occasions, we ask the Almighty for comfort for those who mourn for Zion and those who mourn for Jerusalem…
Our tradition teaches: when a person whitewashes his house, let him not whiten it completely; when a person prepares a meal, let him reduce a little; when a woman puts on jewelry, let him reduce a little, as it is said: "If I forget you, O Jerusalem, may my tongue cleave to the roof of my mouth." And everyone who mourns for Jerusalem will be deemed worthy of seeing her joy, as it is written: "Rejoice ye with Jerusalem, and be glad for her, all ye that love her: rejoice for joy with her, all ye that mourn for her" (Isaiah 66:10).