Halakhah sa Isaias 58:13: Mishneh Torah, Rest & Mishneh Torah, Sabbath

In the same way that there is an obligation to honor the Sabbath and to delight in it, so too [is it with] the holidays. As it is stated (Isaiah 58:13) "to sanctify the honored Lord"; and it is stated about all of the holidays (Leviticus 23:7), "a time of holiness." And we have already explained [this] honoring and delighting in the laws of the Shabbat. It is therefore fit for a person to refrain from having a meal on the eve of holidays from the time of the afternoon prayer, like on the eve of Shabbat. As this thing is part of [its] honor. And anyone who disgraces the festivals is as if he was associated with idolatry.

We may not bathe in laxative waters, nor in mud in which [people] drown (quicksand), nor in putrid stagnant waters, nor in the waters of Sodom nor in the bad waters that are in the Great Sea—as all of these are distressing, and it is written (Isaiah 58:13), "and you shall call Shabbat, a delight." Hence, it is permissible if he does not delay in these, but rather comes out immediately—even though he has sores on his head [which will thereby be healed).

Writing is [one] of the primary categories of forbidden work. Hence it is forbidden to apply blue eye powder and that which is similar to it, since it is like writing. And it is forbidden to take a loan or to give a loan, [as a] decree lest one write. Likewise, it is forbidden to buy and sell, to rent and to rent out, [as a] decree lest one write. One may not hire workers on Shabbat, nor say to his fellow to hire workers for him. But it is permissible to borrow and lend [items]: One may borrow barrels of wine and barrels of oil from his fellow, so long as he does not say to him, "Lend me."