《礼记·丧服小记》
诸侯不能衬葬于当过天子的祖父，但天子、诸侯、大夫能够柑葬于当过士的祖父。
诸侯不得祔于天子，天子、诸侯、大夫可以祔于士。
Feudal princes cannot be buried with their grandfather who has been emperor, but emperors, feudal lords, and high-ranking officials can be buried with their grandfather who has been a gentleman.