The seven-day week shows God’s connection with the number 7, or rather the connection of the number 7 with God.
Moses instructed the people about the gathering of the manna on the ground, saying,
“Six days you shall gather it, but on the seventh day, the Sabbath, there will be none. Now it happened that some of the people went out on the seventh day to gather, but they found none” (Exodus 16.26, 27).
God meant what He said, and said what He meant. Therefore, in verse 28 He asked why the people refused to keep His commandments, in this case, referring to resting on the seventh day.
He said further,
“See! For the LORD has given you the Sabbath; therefore He gives you on the sixth day bread for two days. Let every man remain in his place; let no man go out of his place on the seventh day” (Exodus 16.29).
Resting on the seventh day was important to the Lord, and it needed to be important to His people. Finally, they got the message,
“So the people rested on the seventh day” (Exodus 16.30).
Whether they understood the significance of His commands or not, such as resting on the seventh day of every week, they were to do as He said.
God does not command Christians to rest on the seventh day, but He does command us to do other things, and He means it as much as His commanding the children of Israel to rest on the seventh day.