“…the earth shall rest a Sabbath to Hashem.” (Leviticus 25:2)
This passage refers to the Sabbatical year in Israel where the land was left and not worked every seventh year.
The Baal Shem Tov saw here a cue for us – to give earthiness (the physical and material aspects of life) a rest and to focus on spirituality and holiness.
A general emphasis in Torah is that we should prioritize spiritual over materialistic pursuits in life. In a famous Midrash, the letter Aleph (first letter in the alphabet) complained to God because the Torah begins its account of the creation of the world with the letter Bet (second letter of the alphabet) in the word Bereshis – in the beginning. God comforted the Aleph by telling it that the Ten Commandments would begin with an Aleph. Indeed, the first word of the Ten Commandments – Anochi, begins with the letter Aleph.
Rav Zalman Sorotzkin notes that the first letter of the alphabet is associated with the spiritual teachings of the Ten Commandments revealed at Mt.Sinai while the second letter is associated with the creation of the physical world. He suggests that the lesson here is that the Aleph, first place of our lives should be in the realm of spirituality while the Bet or secondary focus of our lives should be in the earthly/worldly realm.