This incident illustrates the fate of the Israelite or foreigner in Israel who deliberately violated the law of Sabbath observance. It clarifies the meaning of defiant sin as well as what it means to be "cut off from among his people"(vv. 30-31). Violation of this law drew the death penalty (Exod. 31:14-15; 35:2).133God revealed on this occasion that such an offender was to die by stoning (cf. Lev. 20:2). Whereas Moses had previously recorded the penalty he had not explained the method of execution (v. 34).134
"The purpose of these narratives is to show that God's will is not expressed in a once-for-all way. In Israel's ongoing relationship with God, he continued to make his will known to them, and they continued to play a part in the process."135
Sabbath observance was the sign of the Mosaic Covenant. To violate the Sabbath law deliberately amounted to repudiating God's sovereignty.
"There are eleven offenses punishable by stoning according to the Old Testament: idolatry (Deut. 17:2-7); encouragement of idolatry (Deut. 13:6-10); child sacrifice (Lev. 20:2-5); prophecy in the name of another god (Deut. 13:1-5); divination (Lev. 20:27); blasphemy (Lev. 24:15-16); breaking the Sabbath (here); murder by an ox (Exod. 21:28-29); adultery (Deut. 22:22ff.); rebellion by a son (Deut. 21:18ff.); violation of God's ban on plunder devoted to him (Josh. 7:25)."136