Explanation of returning warm to cold at first

At first glance: at first. Hot and cold. Describe the spring and autumn, cold and hot weather is changeable. The source of the idiom: Song Chai Wang's Nian Nujiao says: "There is a fragrant wind everywhere outside the door, and the residual plum is messy, and the jade is broken with moss. Hot and cold, I don't want to try Luo Yi. "

Examples of idioms: For the last spring, eliminate the eternal day.