Exo 16:22 And it came to pass, that on the sixth day they gathered twice as much bread, two omers for one man: and all the rulers of the congregation came and told Moses.
Exo 16:23 And he said unto them, This is that which the LORD hath said, To morrow is the rest of the holy sabbath unto the LORD: bake that which ye will bake to day, and seethe1 that ye will seethe;2 and that which remaineth over lay up for you to be kept until the morning.
Exo 16:24 And they laid it up till the morning, as Moses bade: and it did not stink, neither was there any worm therein.
Exo 16:25 And Moses said, Eat that to day; for to day is a sabbath unto the LORD: to day ye shall not find it in the field.
EAV Exo 16:26 Six days ye shall gather it; but on the seventh day, which is the sabbath, in it there shall be none.
EAV Exo 16:27 And it came to pass, that there went out some of the people on the seventh day for to gather, and they found none.
EAV Exo 16:28 And the LORD said unto Moses, How long refuse ye1 to keep my commandments and my laws?
EAV Exo 16:29 See, for that the LORD hath given you the sabbath, therefore he giveth you on the sixth day the bread of two days; abide ye every man in his place, let no man go out of his place on the seventh day.
EAV Exo 16:30 So the people rested on the seventh day.
This is what you are referring to I suppose.
Westminster Confession of Faith
Chapter 21
7. As it is the law of nature, that, in general, a due proportion of time be set apart for the worship of God; so, in His Word, by a positive, moral, and perpetual commandment binding all men in all ages, He has particularly appointed one day in seven, for a Sabbath, to be kept holy unto him:(34) which, from the beginning of the world to the resurrection of Christ, was the last day of the week: and, from the resurrection of Christ, was changed into the first day of the week,(35) which, in Scripture, is called the Lord's Day,(36) and is to be continued to the end of the world, as the Christian Sabbath.(37)
8. This Sabbath is then kept holy unto the Lord, when men, after a due preparing of their hearts, and ordering of their common affairs beforehand, do not only observe an holy rest, all the day, from their own works, words, and thoughts about their worldly employments and recreations,(38) but also are taken up, the whole time, in the public and private exercises of His worship, and in the duties of necessity and mercy.(39)