God always says what He means and means what He says, including when He gave Israel the seventh day as a day of rest, regardless of its inconvenience,

“Six days you shall work, but on the seventh day you shall rest; in plowing time and in harvest you shall rest” (Exodus 34.21).

The seventh day was that important to God, and He wanted it to be as important to the children of Israel.

Even during times of heavy work, such as plowing and harvesting, they had to observe the day of rest.