Filling the Gaps: Exodus and Mekhilta d'Rabbi Ishamael

(12) And יהוה said to Moses:(13) Speak to the Israelite people and say: Nevertheless, you must keep My sabbaths, for this is a sign between Me and you throughout the ages, that you may know that I יהוה have consecrated you.(14) You shall keep the sabbath, for it is holy for you. One who profanes it shall be put to death: whoever does work on it, that person shall be cut off from among kin.(15) Six days may work be done, but on the seventh day there shall be a sabbath of complete rest, holy to יהוה; whoever does work on the sabbath day shall be put to death.(16) The Israelite people shall keep the sabbath, observing the sabbath throughout the ages as a covenant for all time:

(1) (31:13) "but My Sabbaths shall you keep": What is the intent of this? From (Ibid. 20:10) "You shall not perform any labor," I would know only of labor per se. Whence would I derive (the same for) shvuth ("resting," things bordering upon labor)? It is, therefore, written "but My Sabbaths shall you keep," to include shvuth.

(2) R. Yishmael and R. Elazar b. Azaryah and R. Akiva were once walking on the road, with Levi Hasadar and R. Yishmael the son of R. Elazar b. Azaryah walking behind them, when this question was asked: Whence is it derived that the saving of a life overrides the Sabbath? R. Yishmael responded: It is written (Ibid. 22:1) "If the thief be found breaking in, etc." — If in such an instance, where it is doubtful whether he is coming to steal or to kill, and the spilling of blood defiles the land and causes the Shechinah to depart, he is permitted to kill the thief to save his life — how much more so does the saving of life override the Sabbath! R. Elazar b. Azaryah responded: If circumcision, which includes only one of a man's organs, overrides the Sabbath, how much more so all of his body! R. Akiva says: If the saving of a life overrides the sacrificial service, which overrides the Sabbath, how much more so does the saving of a life override the Sabbath! R. Yossi Haglili says: "My Sabbaths shall you keep": "but" ("ach," before "My") "divides," i.e., there are Sabbaths that you override, and there are Sabbaths that you rest. R. Shimon b. Menassia says (Ibid. 14) "And you shall keep the Sabbath, for it is holy to you" — Sabbath is given to you and you are not given (i.e., "surrendered") to the Sabbath. R. Nathan says (Ibid. 16) "And the children of Israel shall keep the Sabbath to observe the Sabbath for their generations": Desecrate one Sabbath in order to keep many Sabbaths.

(3) (Ibid. 13) "for it is a sign between Me and you": and not between Me and the peoples of the world. "for your generations": to be observed throughout the generations. "to know that I, the L rd, sanctify you": What is the intent of this? From (Ibid. 16) "And the children of Israel shall keep the Sabbath," I might think, even a deaf-mute, an imbecile, and a minor. It is, therefore, written "to know that I, the L rd, etc." I spoke only of one who has knowledge (to internalize this.) "that I, the L rd, sanctify you": in the world to come, as with the sanctity of Sabbath in this world — whence we derive that the sanctity of Sabbath is of a kind with that of the world to come. And thus is it written (Psalms 92:1) "A psalm, a song for the day of Sabbath" — for the world which is all Sabbath.

(1) Resting from labor on the seventh day fulfills a positive commandment, as [Exodus 23:12] states, "And you shall rest on the seventh day." Anyone who performs a labor on this day negates the observance of a positive commandment and also transgresses a negative commandment, for [ibid. 20:10] states, "Do not perform any labor [on it]."
What are the liabilities incurred by a person who performs labor [on this day]? If he does so willingly, as a conscious act of defiance, he is liable for karet; if witnesses who administer a warning are present, he should be stoned [to death]. If he performs [labor] without being conscious of the transgression, he is liable to bring a sin offering of a fixed nature.