Vayakel pekudai

As the Torah recounts the building of the mishkan and everything that went into it, it starts with instructing us to keep the Shabbos holy. ששת ימים תעשה מלאכה​, for a period of six days work may be done, וביום השביעי יהיה לכם קודש,but the seventh day shall be holy to you, a day of complete rest for Hashem.

In the Friday night zemiros we say כל מקדש שביעי כראוי לו, whoever sanctifies the Shabbos as befits it, כל שומר שבת כדת מחללו, whoever safeguards the Shabbos properly from desecrating it, שכרו הרבה מאד על פי פעלו, his reward is exceedingly great in accordance with his deed.

The Chafetz Chaim says that this is referring to two different types of people that keep Shabbos. There are those who infuse the Shabbos with a special​ holiness, who spend the whole time with Torah and holiness; on them it's said: כראוי לו, as befits the Shabbos. That's why Shabbos was created, to infuse in us a holiness that lasts the week. Then, there are people that are שומר שבת כדת מחללו, that keep the Shabbos by refraining from doing anything wrong but don't necessarily pursue holiness on that day. They just use it to eat sleep and drink. While both types of people are described שכרו הרבה מאד, the reward is very great, each one, though, will get על פי פעלו, according to his deed.

What kind of person is this really referring to; what does it mean according to his deed?

One of the interesting things about the laws of Shabbos is that the only way one can transgress and be held liable is if one had intent to do the action. For example, if two people pulled a flower out of the ground and one of the people had thought that the flower was already detached, he wouldn't be liable.  Two people can both do the exact same action, yet the one with will be liable while the other one, who didn't have intent, wouldn't be liable. Maybe we can explain על פי פעלו , according to his deed a little differently.

There was a story in Radin about one of the shopkeepers who would keep his store open late on Friday after Shabbos started and open up early Saturday night before Shabbos ended. The Chafetz Chaim spoke to him and said that what he's doing is like the farmer who was selling his apples wholesale; in order to keep count of all the bags of apples, for each bag that was sold, the buyer would put a coin in a bowl. When they were done, they would count the coins and then he would get paid for each bag based on how many coins there were.

As the bowl filled up, the farmer, being a little greedy, made sure no one was looking and stole some of the coins, not realizing that, for every coin he stole, he was actually losing the price of a whole bag of apples. What he took and thought he was gaining, was really losing so much more. So, too, continued the Chafetz Chaim. Hashem gave us the Shabbos. For every hour of Shabbos observance, we are blessed throughout the week. When you steal from these hours, you are only stealing from yourself.

The farmer’s intent was to steal; however, he ended up only stealing from himself. When a person keeps Shabbos, his merit is based on intent, not action. One who, perhaps, only knows how to keep the Shabbos by refraining from doing anything wrong or just by eating and sleeping, hasr intention to be able to keep the Shabbos properly. He might even look forward to it and feel more closely connected to it than someone who, in practice, does the more holy things. That's why it says at the end of the song, על פי פעלו, according to his deed, his reward will be according to his deed. If it was just about what one actually did, it would have used a word like עשה that means according to what he did.  Instead, it uses the word פעלו, which can also be translated to mean influence, telling us that the reward one gets for keeping Shabbos is not about what one actually does but rather what his intent is and what influence the Shabbos has on him. Let's take this opportunity to increase out awareness of Shabbos, feeling connected and letting its influence stay with us throughout the week!