Old symbol: refers to the old Spring Festival couplets (last year's Spring Festival couplets)
1. In ancient times, two red wooden boards were hung on the gate, on which the door keeper was painted or his name was written to ward off evil spirits.
2. Because later generations often put Spring Festival couplets on peach symbols, later generations use "peach symbols" to refer to Spring Festival couplets.
Always changing new peaches for old ones means changing new Spring Festival couplets for old ones. In the Song Dynasty, the meaning of Fu Tao was already Spring Festival couplets.