Большой китайско-русский словарь
yǎng bīng qiān rì, yòng zài yī zhāo
[Aimies are to be maintained in the course of long years, but to be used in the nick of time.Keep sth.seven Years and you will find a use for it] 长期训练一支军队, 是为了在必要时使用的。 比喻长时期的准备是为了在需要时发挥作用的