What does 2 Kings 22:8 mean?

Then Hilkiah the high priest said to Shaphan the secretary, I’ve found the book of the law in the Lord’s temple. Hilkiah gave the book to Shaphan, who read it. 2 Kings 22:8 - Modern Text Bible

(During the repairs, the high priest discovers a lost scroll—probably the core of what we now call Deuteronomy. This is a huge moment.)