ㄕㄣㄘㄤˊㄖㄨㄛˋㄒㄩshēncáng‑ruòxū

深藏若虚
  1. 寶貴物品起來好像東西一樣形容學問顯露 學術造詣高深往往深藏若虛顯示自己」。

to hide one's treasure away so that no-one knows about it (idiom)​; fig. modest about one's talents, to hide one's light under a bushel