Excerpt from <span class="chinese-post-title">十三勢行功要解</span> the Important Explanations for the Accomplishment of the Thirteen Postures by <span class="chinese-post-title">武禹襄</span> Wǔ Yǔxiāng

曲中求直,蓄而後發.

"Look for the straight within the curved, accumulate then emit."

By Wǔ Yǔxiāng (武禹襄), based on the translation by Yang Jwing Ming (楊俊敏) presented in the book Tai Chi Secrets of the Wu & Li Styles (太極拳武李氏先哲秘要) and various translations on the internet.