The Israelites cannot live by rituals alone. The holy land has to be, well, holy. And that's where morality and ethics comes in.
An ethic of mutuality runs through all of Leviticus. Israelites look out for other Israelites. They follow through on their promises. They pay a fair price, don't cheat in business dealings, and don't exploit the weak. Even the rules about things like adultery, incest, and same-sex sexual intercourse might be more about respecting other Israelites than having too much fun.
Oh, and if they muck up the rules and hurt someone in the process, the Israelites have to atone for it by paying a proportional amount. You might say an eye for an eye. Or something like that.