[If] they had been fasting, and rain began to fall before sunrise, they need not complete [the fast]. [If the rain began to fall] after sunrise, they must complete [the fast]. R' Eliezer says: [If it began to rain] before midday, they need not complete [the fast, but if the rain began] after midday, they must complete [the fast]. It once happened that a fast was decreed in Lod and rain fell before midday. R' Tarfon said to them, “Go out, eat and drink, and proclaim a holiday.” They then went out, ate, drank, and proclaimed a holiday. In the afternoon, they returned [to the synagogue] and recited the Great Hallel.