Albert Barnes Commentary Leviticus 25:1

"And Jehovah spake unto Moses in mount Sinai, saying," — Leviticus 25:1 (ASV)

The sabbatical year and the year of Jubilee belong to that great sabbatical system which runs through the religious observances of the Law, but rest upon moral rather than upon formally religious ground. It is not, therefore, without reason that they are here set apart from the set times which fell strictly within the sphere of religious observances.