An empty grain
Konggu Baiju, a Chinese idiom, Pinyin is k ō NGG ǔ B á ij ū, which means that talents cannot be employed. From the book of songs Xiaoya Baiju.
Idiom explanation
Foal: a stout horse. It's a good broken horse, but it's not used in the valley. Metaphor can't employ talents.
The origin of Idioms
[source] book of songs Xiaoya Baiju: "Jiaojiao Baiju, in the empty valley."
An empty grain
judge the hour and size up the situation - shěn jǐ dù shì
Holding the jade and cherishing the gold - wò yú huái jǐn