Final answer:
The phrases suggesting Old Woman Swamp as a symbol of paradise are 'descended into the cool greenness,' 'promise hung about us like the leaves,' and 'birds broke into song,' as they convey serenity and beauty.
Step-by-step explanation:
The phrases in James Hurst's "The Scarlet Ibis" that emphasize Old Woman Swamp as a symbol of paradise for the boys are "descended into the cool greenness," "promise hung about us like the leaves," and "birds broke into song." Each of these phrases evokes a sense of serenity, beauty, and potential, which are qualities often associated with a paradisiacal setting. The cool greenness suggests a refreshing escape from the heat, the leaves represent life and hope, and the singing birds contribute to the aura of natural harmony.