We can still become emotionally tired. We can still become spiritually tired. Emotional and mental fatigue takes a far heavier toll on us than physical fatigue. Physical fatigue can usually be relieved by a few hours of sleep. Mental and emotional fatigue may require us to take a vacation where we can find relief from the stress of our daily lives.
Spiritual fatigue takes the heaviest toll of all.
It may lead to a loss of hope. One may even lose the will to live. The Sabbath can provide a time for rest from every kind of fatigue. On the Sabbath we will remember that God created the world by the spoken word. We remember that God created the Sabbath by declaring it to be holy, set apart from all other days.