The command in Exodus has two types of prohibitions each with its own consequence:
You shall keep the Sabbath, because it is holy for you. Everyone who profanes it shall be put to death. Whoever does any work on it, that soul shall be cut off from among his people. (Exodus 31:14) [ESV]
- Prohibition: profane. Consequence: put to death
- Prohibition: work. Consequence: cut off from among his people
Later application might consider work to be punishable by death, yet the original instruction, which treats working on the Sabbath as an action distinct from profaning the Sabbath, did not require death. The penalty for working on the Sabbath was to be cut off from his people and while death would be one way of accomplishing this, it is clear from the context, the meaning is one of separation. In other words, a person who violates the Sabbath by working, is to be exiled or "cut off" from the rest of the community; which is how the word "cut off" is first used:
Any uncircumcised male who is not circumcised in the flesh of his foreskin shall be cut off from his people; he has broken my covenant.” (Genesis 17:14)
The penalty for breaking the covenant of circumcision was not death; it was to be cut off from the people.
The incident in question then raises three obvious issues:
- Is gathering sticks considered as profaning the Sabbath or working on the Sabbath?
- If profaning the Sabbath, who is to carry out the sentence of death?
- If the consequence is death and if the people are to carry out the sentence, how is that to be accomplished?
Similar to how the sentence is to be carried out (as noted in Der Übermensch's answer), is the question of who and even when the sentence is to be carried out. In her commentary on Numbers Nili S. Fox notes:
The case of the wood gatherer is distinct from the above. It illustrates a most severe violation of the ritual law, the desecration of the Sabbath, which is a capital offense, here punishable by stoning (cf. Exod. 31.14). It is possible that Moses here asks God what to do because earlier legislative texts note the punishment is death, but are unclear about whether it should be carried out by people or God (Exod. 31:14-15).
Finally, the event is placed immediately after a passage (Numbers 15:22-31) which discusses unintentional and presumptuous sin. So another possibility is the question of whether this particular violation was presumptuous or unintentional. In other words, ordinarily gathering sticks is work, but this particular cases is one of deliberately acting to profane the Sabbath.
Given these uncertainties, especially about the man's motivations, Moses asks the LORD how to handle the situation. The LORD's instructions, that the people are to carry out the death sentence by stoning, answers most of the questions.
Although there is nothing in the text which states whether the stoning was done on the Sabbath or the man's motivations, the implication of placing this event in this context may be to illustrate that any presumptuous act will profane the Sabbath. In other words, Moses would wait until after the Sabbath before having the man stoned to preserve the holiness of the day.
- Nili S. Fox, The Jewish Study Bible, Oxford University Press, 2004, p. 314
- For example, the man had no immediate need for the sticks and could have waited until after the Sabbath to get what he desired..