When the declaration of independence states that “all men are created equal,” what document is it paraphrasing from?

The document you are talking about is The Bible.
Naturally, the Bible proposes the idea that all men are equal in the eyes of God, which is why there shouldn't be any discrimination based on skin color or sex. Although Thomas Jefferson did base his ideas on the Bible, that there is no difference between people, racism, slavery, and discrimination based on gender still existed for a very long time in America.