You may rest assured that we will do all we can to find him.

你就放心吧，我们会千方百计找到他。

《牛津词典》

About the quality, you may rest assured.

关于质量您就放心好了。

youdao

You may rest assured. (feel relax or don't worry).

你不用担心。

youdao

For some of you it may be difficult I know that and I want you to rest assured that no one in this course wishes to undermine or malign religious faith any more than they wish to promote or proselytize for religious faith.

我知道对你们中的另一些人来说这门课会有困难,不过我想要你们放心,这门课上没有人想要破灭和诋毁宗教信仰,同样也没人想要劝诱他人信教。

耶鲁公开课 - 旧约导论课程节选

It may not be today, and it may not be for many years, but you can rest assured that at some point there will always be a reckoning.

FORBES: Success Will Come and Go, But Integrity is Forever

This approach may seem like a timely and expensive investment, but you can at least rest assured you have an audience chomping at the bit for this type of content.

FORBES: Get Feedback and Shake Up Your Site