Preheat oven to 325°F. Place ham, cut side down, on rack in large roasting pan; let stand at room temperature 30 minutes. Pour 2 cups water into pan; add lemons and oranges to pan. Loosely cover ham with aluminum foil; bake 1 hour or until internal temperature reaches 90°F.
In small saucepan, whisk molasses, orange juice, mustard, sugar, lemon juice, cinnamon, zest and cloves; heat to a simmer over medium heat and simmer 5 minutes, whisking occasionally. Makes about 4 cups.
Remove ham from oven; brush with some glaze. Bake ham, uncovered, 45 minutes or until internal temperature reaches 130°F, brushing with glaze every 15 minutes. Loosely cover ham with aluminum foil; let stand 15 minutes before serving. (Internal temperature will rise to 140°F upon standing.) Serve ham with remaining glaze.