I agree that he was influenced by Leviticus, but not that he actively used it in his preaching. As you say, he used already common beliefs of the people to teach them the gospel (like his discourse on the "Unknown God" at Mars hill - Acts 17). You can find almost everytihing that I believe in the Old Testiment, but that does not mean I will quote from it in my discussions if I think it would be better to do it differently.

(What exactly are we arguing about?)