It was from Bai Juyi's "Farewell to Ancient Original Grass" of the Tang Dynasty. The whole sentence was: The grass on the plain withers and thrives once a year. The wildfire never ends, and the spring breeze blows, it grows again. The far-off fragrance encroaches on the ancient road, the clear green connecting the deserted city. And send the king's grandson away, full of parting feelings. Among them, the phrase "lonely in the palace, late spring" was not the original sentence but a continuation of the artistic conception in the poem by later generations. This sentence described the emptiness and loneliness in the palace, but it felt cold and desolate when spring was about to arrive.