Book 17: 《陽貨》 Yang Huo
《陽貨》 Passage 17.20
孺悲欲見孔子，孔子辭以疾。將命者出戶，取瑟而歌。使之聞之。
Legge Translation (1861)
Ru Bei wished to see Confucius, but Confucius declined, on the ground of being ill, to see him. When the bearer of this message went out at the door, (the Master) took his lute and sang to it, in order that Bei might hear him.