Twice as much bread - See Exodus 16:5.

From this passage and from Exodus 16:5 it is inferred that the seventh day was previously known to the people as a day separate from all others, and if so, it must have been observed as an ancient and primeval institution.

On the sixth day they gathered twice as much - This they did that they might have a provision for the Sabbath, for on that day no manna fell, Exodus 16:26, Exodus 16:27. What a convincing miracle was this! No manna fell on the Sabbath! Had it been a natural production it would have fallen on the Sabbath as at other times; and had there not been a supernatural influence to keep it sweet and pure, it would have been corrupted on the Sabbath as well as on other days. By this series of miracles God showed his own power, presence, and goodness, 1. In sending the manna on each of the six days; 2. In sending none on the seventh, or Sabbath; 3. In preserving it from putrefaction when laid up for the use of that day, though it infallibly corrupted if kept over night on any other day.

And it came to pass, that on the sixth day,.... Of the week, or from the first raining of the manna, which was the same:

they gathered twice as much bread; as they had used to do on other days, a greater quantity falling, and which was more easily taken up:

two omers for one man; or, "instead of one" (t) of one omer; so it turned out when they came to measure what they had gathered; otherwise they had no intention in gathering it, but lying in a great quantity, they gathered as much as they could, or could well carry, and upon measuring it so it proved; for it does not appear that Moses had as yet acquainted them what was to be, or would be gathered on this day; nor had he any orders so to do from the Lord, only he was told by him that so it would be, and accordingly it came to pass, see Exodus 16:5.

and all the rulers of the congregation came and told Moses; what had happened, that the people that day had gathered as much more as they had used to do on other days: these seem to be the overseers of this affair, before whom what was gathered was brought, and in whose presence it was measured, and who took care that everyone should have his omer and no more: this makes it plain that the people acted without design, and knew not that they were to gather on this day double to other days; since the rulers knew nothing of it, nor of the reason of it, and it can hardly be imagined that the people should know and the rulers be ignorant.

(t) "pro uno", Tigurine version.

Moreover, God bestowed His gift in such a manner, that the Sabbath was sanctified by it, and the way was thereby opened for its sanctification by the law. On the sixth day of the week the quantity yielded was twice as much, viz., two omers for one (one person). When the princes of the congregation informed Moses of this, he said to them, "Let tomorrow be rest (שׁבּתון), a holy Sabbath to the Lord." They were to bake and boil as much as was needed for the day, and keep what was over for the morrow, for on the Sabbath they would find none in the field. They did this, and what was kept for the Sabbath neither stank nor bred worms. It is perfectly clear from this event, that the Israelites were not acquainted with any sabbatical observance at that time, but that, whilst the way was practically opened, it was through the decalogue that it was raised into a legal institution (see Exodus 10:8.). שׁבּתון is an abstract noun denoting "rest," and שׁבּי a concrete, literally the observer, from which it came to be used as a technical term for the seventh day of the week, which was to be observed as a day of rest to the Lord.

And it came to pass, that on the sixth day they gathered {k} twice as much bread, two omers for one man: and all the rulers of the congregation came and told Moses.

(k) Which would serve for the Sabbath and the day before.

16:22-31 Here is mention of a seventh-day sabbath. It was known, not only before the giving of the law upon mount Sinai, but before the bringing of Israel out of Egypt, even from the beginning, Ge 2:3. The setting apart one day in seven for holy work, and, in order to that, for holy rest, was ever since God created man upon the earth, and is the most ancient of the Divine laws. Appointing them to rest on the seventh day, he took care that they should be no losers by it; and none ever will be losers by serving God. On that day they were to fetch in enough for two days, and to make it ready. This directs us to contrive family affairs, so that they may hinder us as little as possible in the work of the sabbath. Works of necessity are to be done on that day; but it is desirable to have as little as may be to do, that we may apply ourselves the more closely to prepare for the life that is to come. When they kept manna against a command, it stank; when they kept it by a command, it was sweet and good; every thing is sanctified by the word of God and prayer. On the seventh day God did not send the manna, therefore they must not expect it, nor go out to gather. This showed that it was produced by miracle.