《礼记·月令》
立春的那天，天子亲自率领三公、九卿、诸侯、大夫到东郊去举行迎春的祭祀。
立春之日，天子亲帅三公、九卿、诸侯、大夫以迎春于东郊。
On the day of Lichun, the emperor personally led the three dukes, nine ministers, princes and high-ranking officials to the east suburb to hold a sacrifice to welcome spring.