We often talk about someone being shomer Shabbat, meaning that they scrupulously observe all of the many laws pertaining to Shabbat. However, a closer understanding of this verse might reveal a different approach to what shomer Shabbat really means.
Chizkuni (Rabbi Chizkiyahu Ben Manoach, 13th-century France), comments on the word veshameru (“they shall observe”) and says, “They shall eagerly await and anticipate… which day of the week will be Shabbat.”
This use of veshamar can also be learned in Genesis (37:11). After Joseph recounts his dreams of leadership to his brothers, it says “His brothers were jealous of him, but his father observed (shamar) the matter”. There Rashi similarly comments and says “Jacob waited in anticipation for the dreams of Joseph to be realised”.
Each morning, at the end of shacharit, we recite a Song of the Day, recollecting the specific daily psalm that the Levites sang in the Temple. Just before we recite the psalm for that day, we add an extra line. On Sunday we say “Today is the first day of the Sabbath”; on Monday, “the second day of the Sabbath” etc. We work our way through the week with one thing on our mind, Shabbat.
This, I believe, is what a true shomer Shabbat is, someone who waits with anticipation all week for Shabbat; someone for whom Shabbat represents the essence of their whole week and the fulfilment of their wishes and dreams. It is someone who sees it as a day not of burdensome laws and restrictions but of true enjoyment and satisfaction. By viewing the Shabbat in this way, we all have the ability to become a true shomer Shabbat.