Question: "What does it mean to remember the Sabbath day and keep it holy?"
Answer: The fourth of the ten commandments is “Remember the Sabbath day, to keep it holy” (Exodus 20:8, ESV). Following the command are statements defining the Sabbath as “the seventh day” (verse 10), dedicating it to “the Lord your God” (verse 10), forbidding all work in it, applying it to everyone in Israel, and citing the basis for it: “For in six days the Lord made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the Lord blessed the Sabbath day and made it holy” (verse 11).
The Israelites under the Mosaic Law were to keep in mind that no work could be done on the seventh day of the week. If we parse the command, we can get a better picture of what it says:
Remember. This is the only command of the ten that starts with the word remember. This could mean that the Sabbath command had been given earlier—in fact, God had decreed a Sabbath rest in Exodus 16:22–30. Or the word remember could simply mean “keep this command in mind” with no reference to an earlier directive. Regardless, the word is emphatic; the children of Israel were not to grow lax in their observation of this command.
The Sabbath day. The word Sabbath comes from a Hebrew word meaning “day of rest.” The Bible specifies that this day of rest is the seventh day of the week, what we would call “Saturday,” or in the Israelite mindset, sundown on Friday until sundown on Saturday. God set the pattern for the Sabbath rest in Genesis 2:2, ceasing from His work of creation on the seventh day. God’s action (or, rather, His inaction) in Genesis 2 foreshadowed the Law’s command in Exodus 20:8.
To keep it holy. This four-word phrase in English is only one word in Hebrew. It means “consecrate,” “set apart,” or “sanctify.” The Israelites were to make a distinction between the seventh day and the rest of the week. The Sabbath was different. It was to be dedicated to the Lord. The priests were to double the daily sacrifices on the Sabbath (Numbers 28:9–10), marking the day with increased sacred activity. The rest of the Israelites were to mark the day with decreased activity—no work at all—in honor of the Lord. The penalty for desecrating the Sabbath with work was death (Exodus 31:14; Numbers 15:32–36).
Keeping of the Sabbath was a sign of the covenant between Israel and the Lord: “You must observe my Sabbaths. This will be a sign between me and you for the generations to come” (Exodus 31:13). As Israel kept the Sabbath set apart, they were reminded that they were also being set apart: “So you may know that I am the LORD, who makes you holy” (verse 13). Believers today, being under the New Covenant, are not bound to keep the sign of the Old Covenant.