Targum Pseudo-Jonathan on Exodus 16:5 reads the Sabbath instructions for the manna as a halakhic footnote to the whole story: And on the sixth day they shall prepare what they set before them to eat on the day of the Sabbath; and they shall mix in the houses and communicate in their dwellings, so that by carrying this to that, they may have double of that which they gather from day to day.
The phrase they shall mix in the houses is not poetic. It is technical. The Aramaic yeshateph b'vatey points directly to the rabbinic institution of the eruv chatzerot, the legal fiction of "mixing courtyards" that allows observant Jews to carry between homes and shared spaces on the Sabbath. The Targumist is retro-projecting the classical Sabbath observance into the wilderness: even at the moment of the first manna, the Sages imagined, Israel was already learning the architecture of Shabbat.
The double portion on the sixth day carries the same message. It is a promise wrapped in a command. You will gather twice as much, the Targum says, so that by carrying this to that, your Sabbath will be a day of rest, not of scavenging. The double portion is the Holy One's way of guaranteeing that the day of rest will actually be restful.
The Maggid finds this very moving. The first Sabbath after the exodus from Egypt had to be planned for. You cannot stumble into rest. You cannot rest on Friday night if you have not prepared on Friday afternoon. The Holy One, through Moses, was teaching a freed nation of slaves that freedom requires forethought.
Takeaway: a rest you have not prepared for is not rest. It is exhaustion in a nicer room. Gather on the sixth day what you will need on the seventh. That is what Shabbat is: a gift you receive by first making space for it.