'It is Written' in the Bible

Then Jehoiada put the oversight of the Lord’s temple into the hands of the Levitical priests, whom David had appointed over the Lord’s temple, to offer burnt offerings to the Lord as it is written in the law of Moses, with rejoicing and song ordained by David.

However, he did not put their children to death, because—as it is written in the Law, in the book of Moses, where the Lord commanded—“Fathers must not die because of children, and children must not die because of fathers, but each one will die for his own sin.”