Midrash comes from a Hebrew word that means investigation, interpretation or exposition. Most Midrashim (the plural form of midrash) are continuous exegetical1 commentaries on various books of the Bible. An example of midrashic exposition is mentioned in the Book of Nehemiah (8:8), “So they (the priests) read in the book in the law of God distinctly, and gave the sense, and caused (the people) to understand the reading.”
The Midrash Rabbah (the Great Midrash ) is a collection of Midrashim on the Torah and other books of the Bible. Genesis Rabbah, Leviticus Rabbah, Lamentations Rabbah and Esther Rabbah were probably edited in Israel c. 400-500 ce. “Ruth Rabbah, like Song of Songs Rabbah and Ecclesiastes Rabbah, occupies an intermediate position between the older Midrashim ... and the later Midrashim such as Exodus Rabbah and Deuteronomy Rabbah.”2 Exodus Rabbah “was a product of the eleventh and twelfth centuries.”3 Numbers Rabbah I “cannot be much older than the twelfth century of the common era,”4 whereas Numbers Rabbah II dates to an earlier period (c. 775-900 ce).5
The separate volumes of the Midrash are divided into chapters and sections. The chapter divisions, however, do not necessarily correspond to the chapter divisions of the Bible, nor even to the weekly Torah portion that they comment upon. Numbers Rabbah 1:7, does not correspond to the Book of Numbers, chapter 1, v. 7, but to chapter 1, section 7 of Numbers Rabbah. Actually, the first nine sections of chapter 1 deal with alternative expositions of Numbers 1:1.
The volumes of the Midrash may also be referred to (and frequently are) by their Hebrew names as well, e.g., Genesis Rabbah = Bereshit Rabbah and Lamentations Rabbah = Ekah Rabbah.
1 “Exegetical”—from exegesis, the exposition, critical analysis, or interpretation of a word or passage.
2 Rabbi Dr. L. Rabinowitz, M.A., PH.D., (translator) Ruth Rabbah (The Soncino Press, 1983), p. vii.
3 Rabbi Dr. S. M. Lehrman, M.A., PH.D., (translator) Exodus Rabbah (The Soncino Press, 1983), p. vii.
4 Judah J. Slotki, M.A., (translator) Numbers Rabbah I (The Soncino Press, 1983), p. vii.
5 Encyclopædia Judaica, Vol. 11, (Keter Publishing House, 1972), p. 1511.