hold your horses 耐心一点;稍安勿躁;慢慢来;等一等

【例句】
Hold your horses and take care not to expose your identity.
沉住气，千万别暴露你的身份。

Hey man, just hold your horses. I'm sure you're gonna make it.
嘿哥们儿，别急，稍安勿躁，我相信你能做到的。