Charles Ellicott Commentary Leviticus 18:5

"Ye shall therefore keep my statutes, and mine ordinances; which if a man do, he shall live in them: I am Jehovah." — Leviticus 18:5 (ASV)

You shall therefore keep my statutes. Better, and you shall keep my ordinances. The word here rendered as “statutes” is the same that the Authorized Version translates as ordinances in Leviticus 18:3-4.

He shall live in them. —Better, he shall live by or through them; that is, by observing them, the law-abiding will live a happy and prosperous life, since disobedience will expose the offender to the penalty of death.

The spiritual authorities in the time of the Second Temple interpreted this clause to mean that he who obeys these laws shall have eternal life. Hence, the ancient Chaldee Versions translate it, “Shall have life eternal.” This passage is quoted both in the Prophets (Ezekiel 20:11; Ezekiel 20:13; Ezekiel 20:21; Nehemiah 9:29) and by St. Paul (Romans 10:5; Galatians 3:12), who contrasts this promise made to works with the promise of the Gospel made to faith.