弘明集 8.77

8.77

釋曰。人哭亦哭。俗內之冥跡。臨喪能歌。方外之坦情。原壤喪親登木而歌。孔子過而不非者。此亦是名教之一方耳。

The response says: Wailing when others wail is the trace of conformity within the secular realm; being able to sing when confronting mourning is the candid sentiment beyond the realm. When Yuan Rang lost his parent, he climbed a tree and sang; that Confucius passed by without condemning him was simply a certain aspect of the teaching of names.