Moses reminded Israel of the Ten Commandments, which included the commandment for the Israelites to remember the Sabbath day,
“Observe the Sabbath day, to keep it holy, as the Lord your God commanded you. Six days you shall labor and do all your work, but the seventh day is the Sabbath of the Lord your God. In it you shall do no work: you, nor your son, nor your daughter, nor your male servant, nor your female servant, nor your ox, nor your donkey, nor any of your cattle, nor your stranger who is within your gates, that your male servant and your female servant may rest as well as you. And remember that you were a slave in the land of Egypt, and the Lord your God brought you out from there by a mighty hand and by an outstretched arm; therefore the Lord your God commanded you to keep the Sabbath day” (Deuteronomy 5.12–15).
The Lord made Himself clear, declaring that the Israelites could work six days, but then they had to rest on the seventh day, and that included every person, and even their animals.
In Exodus 20, the Lord had revealed the reason for this pattern, that He had created the world in six days, then rested the seventh day, and He wanted the nation of Israel to follow that pattern.
Then here in Deuteronomy 5.15, He revealed yet another reason why He wanted them to observe the Sabbath, that He had delivered them out of Egyptian bondage.
This reveals that the Lord intended Sabbath-keeping for the nation of Israel only, because He has not delivered any other nation out of Egypt.
If you desire to observe the Sabbath, that is fine, but do not bind it upon anyone who is not of the nation of Israel.