The Israelites must guard the Sabbath, establishing the Sabbath throughout their generations as an everlasting covenant.
The phraseology of this verse implies that there are two dimensions of the Sabbath: one that we are intended to “guard” (or “protect”) and another that we are intended to “establish” (or “make”).
The Sabbath is intrinsically holy, inasmuch as G-d sanctified it when He created the world. Our task with respect to this intrinsic holiness is simply to “protect” it, that is, be careful not to counteract or sabotage it. This we do by not performing forbidden types of work, and, more subtly, by aligning our demeanor with the holy character of the day.
Beyond this, however, we can also infuse additional holiness into the Sabbath, over and above its own, intrinsic holiness. We do this by studying the Torah, praying, or performing acts of kindness to a greater extent or more intensely than usual. In this way, we also “make” the Sabbath holier than it is in and of itself.
—from Daily Wisdom 3