Leviticus 18 lists prohibited sexual unions and practices; Leviticus 20 revisits many of the same offenses and adds judicial or covenant consequences. The two chapters are complementary: chapter 18 emphasizes prohibited conduct and land defilement, while chapter 20 emphasizes penalties, holiness, and separation from surrounding nations.

Leviticus 15 defines menstrual impurity and its duration. Leviticus 18 later prohibits sexual intercourse during that period, using the established niddah category as the legal background for a moral/sexual prohibition. The second passage therefore depends on the purity status described earlier without implying that ritual impurity itself is moral sin.

The rare Greek term arsenokoitai in 1 Corinthians 6:9 is widely argued to echo the Septuagint wording of Leviticus 18:22 and 20:13 (arsenos + koite word field). Exact semantic scope in Paul remains debated.

The Jerusalem Council's prohibition of porneia is often connected with Leviticus 17–18 rules applicable to resident aliens, but the exact content and Torah background of the decree remain debated.

Acts 15 prohibits Gentile believers from things polluted by idols, sexual immorality, strangled meat, and blood. Many interpreters see a strong background in Leviticus 17–18, where resident aliens as well as Israelites are addressed in clustered rules about sacrifice, blood, and sexual conduct. The correspondence is serious but debated because the council never names Leviticus 17–18 as its source.