Mekhilta is an Aramaic word corresponding to the Hebrew middah, meaning a “measure” or “rule”, in this case referring to certain fixed rules of scriptural exegesis used in halakhic midrash. Though there are other works known as Mekhiltot, the title “Mekhilta” by itself usually refers to a compilation of halakhic midrash on Exodus, the Mekhilta deRabbi Ishmael, excerpted below. (The Rabbi Ishmael referred to in this case is R. Ishmael ben Elisha, a contemporary of R. Akiba.)
It is unlikely that R. Ishmael is really the author of the final work, though many of his interpretations are included in the Mekhilta, and the midrash halakhah within it falls within his school of interpretation. However, the majority of the Mekhilta actually consists of midrash aggadah, which expands upon biblical narrative, or deals with ethical or spiritual question.
The following is taken from Tractate Piskhah (Aramaic for Passover), chapter 15, a commentary on Exodus 12:43-49 (from Parashat Bo). This is one of the legal sections, gives the reader a sense of how midrash halakhah works with the biblical text. It is excerpted from Mekhilta de-Rabbi Ishmael, vol. 1 (translation) by Jacob Z. Lauterbach, published by the Jewish Publication Society.
And the Lord Said unto Moses and Aaron: This is the Ordinance of the Passover (Offering. There shall no alien eat thereof) (Exodus 12:43)
There are some sections in which the general statement comes first and the particular follows, and some in which the particular comes first and the general follows: And ye shall be unto me a kingdom of priests and a holy nation” (Exodus 19:6), is a particular statement. “These are the words which thou shalt speak unto the children of Israel” (ibid.), is a general statement. “This is the statute of the Law” (Numbers 19:2), is a general statement. “That they bring thee a red heifer, faultless” (ibid.), is a particular statement. “This is the ordinance of the Passover,” is a general statement. “There shall no alien eat thereof,” is a particular statement. When a general statement is followed by a particular, it does not include more than is contained in the particular (the fourth of the thirteen rules of interpretation of R. Ishmael).
This is the Ordinance of the Passover (Offering).
Scripture here deals with both the Passover of Egypt and the Passover of subsequent generations–these are the words of R. Josiah. R. Jonathan says: This passage deals with the Passover of Egypt, and hence [from it] I would know only about the Passover of Egypt. How do I know about the Passover of subsequent generations? Scripture says: “According to all the statutes of it, and according to all the ordinances thereof, shall ye keep it” (Numbers 9:3).
Said R. Josiah to him: This passage as well as that one deals with both the Passover of Egypt and the Passover of subsequent generations. Why, then, does Scripture have to say: “According to all the statutes of it, and according to all the ordinances thereof?” It merely aims to teach thereby that even those laws which are omitted (from those passages) in the regulations for the Passover of subsequent generations (but which are stated in the regulations about the first Passover) are applicable to it. R. Isi the son of Akiba says: This ordinance prescribed for the Passover applies only to the body of the paschal lamb.
There Shall No Alien Eat Thereof, meaning both an apostate Jew and a Gentile, for it is said: “Thus saith the Lord God: No alien, uncircumcised in heart and uncircumcised in flesh, shall enter into My sanctuary, even any alien that is among the children of Israel” (Ezekiel 44:9).
But Every Man’s Servant (that is Bought for Money)…(Exodus 12:44a): From this I would know only about the servant of a man. How about the servant of a woman or a minor? Scripture says: “That is bought for money,” no matter who owns him.
When Thou Hast Circumcised Him, Then Shall He Eat Thereof. (12:44b)
“He” refers to the master. This tells that failure to circumcise one’s slaves debars one from partaking of the paschal lamb. So far I know only about the circumcision of slaves. How about the circumcision of free males? You can reason as follows: The expression–“then” (az) is used here and the expression “then” (az) is used further on (v. 48). Just as further on it refers to the circumcision of free males, so here it refers also to the circumcision of free males. And just as here it refers to the circumcision of slaves, so there it refers also to the circumcision of slaves–these are the words of R. Eliezer.
R. Ishmael says: Failure to circumcise one’s slaves does not debar one from partaking of the paschal lamb. Why then is it said: “When thou hast circumcised him”? Suppose a man has uncircumcised slaves. How would you know that if he wishes to circumcise them and let them partake of the paschal lamb, he is permitted to do so? Scripture, therefore, says: “When thou hast circumcised him; then shall he eat thereof.”
And we do find that one is permitted to keep uncircumcised slaves, for it is said: “And the son of thy handmaid, and the stranger may be refreshed” (Exodus 23.12). R. Eliezer says: One is not permitted to keep uncircumcised slaves, for it says: “And thou shalt circumcise him.” If so, why then does Scripture need to say: “And the son of thy handmaid, and the stranger may be refreshed?” It is merely for this: Suppose his master bought him Friday afternoon towards nightfall, so that he had not sufficient time to circumcise him before it got dark. It is for such a case that Scripture says: “And the son of thy handmaid . . . may be refreshed.”
Another Interpretation: When Thou Hast Circumcised Him, Then Shall He Eat Thereof. Why is this said? To include one upon whom circumcision had been performed though without permanent effect. Even though the flesh has again covered the corona, he is not debarred from partaking of the paschal lamb or of terumah (the portion of the crop given to the priest). On this question our teachers in Lud took a vote and decided that such a regrowth does not constitute an interposition in regard to uncleanness (that is, since the regrown foreskin doesn’t prevent the removal of uncleanness through immersion in the ritual bath, it is therefore acceptable in this context as well).
A Sojourner and a Hired Servant Shall Not Eat Thereof. (12:45)
“Sojourner” means a resident alien (who is not yet a proselyte, but has given up idolatry). “Hired servant” here means a Gentile. R. Eliezer says: “A sojourner and a hired servant shall not eat thereof.” Why is this said? So that we may be able to prove from the law about the paschal lamb that an uncircumcised person is disqualified from eating terumah.
But even if Scripture had not said this, I could have reasoned: If in the case of the paschal lamb, the less weighty, an uncircumcised person is disqualified from partaking of it, is it not a logical inference that in the case of terumah, the more weighty, an uncircumcised person should be disqualified from eating it? No! If you cite the case of the paschal lamb, Scripture limits the time of eating it even for those who are to eat it, and therefore it disqualifies the uncircumcised person from eating it.
But will you argue the same about terumah, in the case of which Scripture does not limit the time of eating it for those who may eat it? Since Scripture does not put any limit to the time in which it may be eaten, it is but logical to assume that we should not disqualify the uncircumcised from eating it. However, Scripture uses the expression “a sojourner and a hired servant,” in the case of the paschal lamb and in the case of terumah.
Hence, just as the expression “a sojourner and a hired servant,” used in the case of the paschal lamb, disqualifies an uncircumcised person, so also the expression “a sojourner and a hired servant,” used in the case of the terumah disqualifies an uncircumcised person.
R. Isaac says: “A sojourner and a hired servant shall not eat thereof.” Why is this said? Has it not already been said: “There shall no alien eat thereof?” Answer: From the latter I might understand that a circumcised Arabian or a circumcised Gibeonite is qualified to partake of the paschal lamb. Therefore Scripture says: “A sojourner and a hired servant shall not eat thereof.”
In One House Shall lt Be Eaten. (12:46)
Scripture here means in one group. You interpret it to mean in one group, perhaps “in one house” is to be taken literally? When it says: “Upon the houses wherein ye shall eat it” (v. 12), we learn that it may be eaten in more than one house. Hence, what does Scripture mean by saying here “in one house shall it be eaten?” Scripture here means in one group.
And how am I to maintain the expression: “Upon the houses wherein ye shall eat it?” They said on the basis of this expression, that the paschal lamb may be eaten in two places, but may not be eaten in two companies–these are the words of R. Simon the son of Yohai. In two places! How? If they are inside the house and a beam over their heads breaks, they go out to the yard. If they are in the yard and rain comes down upon them, they go inside. Thus they may eat it in two places.