Charles Ellicott Commentary Leviticus 26:2

"Ye shall keep my sabbaths, and reverence my sanctuary: I am Jehovah." — Leviticus 26:2 (ASV)

You shall keep my sabbaths ... — This is exactly the same precept laid down in Leviticus 19:30, and is here repeated because of the danger of desecrating the Sabbath to which the Israelite is exposed who sells himself to a pagan. The Israelite will effectively guard against idol-worship, by keeping the Sabbath holy, and revering God’s sanctuary.