Sons/children of a quality
Here’s what it means
A “son” or “child” of something is a person marked by that quality, destiny, group, or way of life.
Why the Bible says it this way
An idiom is a familiar phrase whose meaning comes from the whole expression, not from reading each word by itself.
A helpful detail: Examples include sons of Belial, sons of light, sons of peace, and children of wrath. The phrase describes character or belonging.