The term “law” in the English Bible derives from the Greek word nomos, and nomos itself is a translation of the Hebrew word Torah. In the Hellenistic period that extended from the third century B.C. to the first century B.C. onward, the original Hebrew word Torah was rendered by nomos, which was the Greek word for “law.” The Septuagint (usually represented by the Roman numeral LXX) is the most important Greek version of the Hebrew Bible coming from the Hellenistic period, and it constantly translates the word Torah as nomos. Because the early Greek-speaking Jews and Christians used the Septuagint as their Scriptures, its impact on Jewish and Christian Greek documents is beyond description.

The Hebrew word Torah, however, does not always mean the law as we normally understand law today. Sometimes Torah means “instruction” or “teaching,” and the term particularly refers to the instructions and teachings of God given to the children of Israel through Moses at Mount Sinai. The Jewish people believe that these teachings are now contained in their sacred book, which is the same one that Christians call the Old Testament. It should also be understood that in a narrow sense Torah refers specifically to the Pentateuch, the name given to the first five books of the Old Testament: Genesis, Exodus, Leviticus, Numbers, and Deuteronomy. The Pentateuch is sometimes called “the book of the Law of Moses” (Josh 8.31; 2 Kgs 14.6; Neh 8.1) or simply “the Law of Moses” (1 Kgs 2.3; Ezra 3.2; Dan 9.11; Luke 2.22).

The Law also meant the “Law of the Lord” (Luke 2.23, 24, 39). It is the will of the Lord; the Law is not simply a legal code but a totality of the revelation of God. It gives the people of God instructions on how they should live justly and how they should carry on their ordinary lives by showing mercy to their neighbors. The Law includes detailed instructions about how the Israelites should prepare and offer sacrifices to their God. It also shows them how to make distinctions between clean and unclean foods and other things, and it teaches them how to deal with criminal justice in their community. But as Jesus summarized so well, “The weightier matters of the Law” are “justice and mercy and faith” (Matt 23.23). The Pentateuch does contain legal codes, but they are to be understood as the will or teachings of God.

When we look back into the history of the Bible, it is evident that the Old Testament has a long process of development. First the Law came into existence, and that was followed by the prophetic writings and then the rest of the Old Testament books, which are called the Hagiographa. So the Law is one of the three major sections of the Old Testament, and each section has its own history of formation and collection. The Law was recognized as Scripture much sooner than the Prophets and the Hagiographa. At the time of Jesus the last section of the Old Testament did not yet enjoy canonical status; it was only late in the first century A.D. that Jewish people recognized the Hagiographa as part of their Scriptures.

The Gospels, therefore, constantly mention “the Law and Prophets” when they refer to the Scriptures. That phrase was synonymous with the Bible at the time of Jesus. “After the reading of the Law and the Prophets, the officials of the synagogue …” (Acts 13.15), “do not think that I have come to abolish the Law or the Prophets” (Matt 5.17), and “on these two commandments hang all the Law and the Prophets” (Matt 22.40) are just a few examples. There are eight other instances in the New Testament where the expression Law and Prophets is used to denote the Bible of that time—Matthew 7.12; 11.13; Luke 16.16; 24.44; John 1.45; Acts 24.14; 28.23; Romans 3.21. Quite often, however, either Law or Prophets may stand by itself and still have the same meaning, that is, the Scriptures. For instance, in the New Testament there are passages like “have you not read in the Law that …” (Matt 12.5) and “so that the Scriptures of the prophets may be fulfilled…” (Matt 26.56). Similar instances are also found in Matthew 2.23; 5.18; 12.5; Luke 2.22, 23; 16.29; 18.31; 24.27; and John 6.45.

The purpose and meaning of the written Law or Torah, now codified in the Pentateuch, emanates from the Ten Commandments, which specify the covenant relationship between God and the Israelites. The “covenant code” or the “book of the covenant” (Exod 24.7) immediately follows the giving of the Ten Commandments (Exodus 20). The Covenant Code (Exod 21–23) generally deals with civil and criminal laws, and consequently the literary form of the code takes a familiar legalistic structure.

There are two forms in the legal code: casuistic and apodictic. The casuistic form is found in the first section of the Covenant Code (Exod 21.1–22.17), and the apodictic form is found in the second section (Exod 22.18–23). The casuistic form first states a condition (the technical term for this is “protasis”) that normal begins with words like “if” or “when.” The protasis describes the circumstances or conditions that prompt the consequential injunctions. The second part, that is, the injunction, is called “apodosis.” It contains a statement of legal consequences that may or may not begin with the word “then.” Here are two examples: “When a man sells his daughter as a slave, she shall not go out as the male slaves do” (Exod 21.7) and “If someone’s ox hurts the ox of another, so that it dies, then they shall sell the live ox and divide the price of it” (Exod 21.35).

The apodictic form, usually found in the second part of the Covenant Code, states commands in the second person “you.” It gives commandments or prohibitions in direct forms without any description about circumstances. For example, we read in Exodus 22 “You shall not permit a female sorcerer to live. Whoever lies with an animal shall be put to death” (vv. 18–19) and “You shall not revile God, or curse a leader of your people” (v. 28). This apodictic form is most common in other legal codes like the Priestly and Holiness Codes.

The Priestly Code is another legal document found in parts of Exodus, Numbers, and Leviticus. It specifically deals with matters related to religious concerns and ritual procedures. Perhaps the oldest and most distinct section of this code is the Holiness Code in chapters 17–26 of Leviticus. The basic theological thrust of this code is stated in the following passage: “You shall be holy, for I the Lord your God am holy” (Lev 19.2).

The book of Deuteronomy, as the name indicates (it means the “second law”), contains legal codes pertaining to kingship, human relations, family life, and civil and cultic matters. It is a comprehensive guide to every aspect of community life, even though it constantly reminds the readers about the history of God’s dealings with Israel. The core of this book became the source of King Josiah’s reform in 621 B.C. The written Law reflects not only the nomadic life before the settlement in the promised land, but it also presupposes the social milieu of Israel during the times of the kingdoms.

Although the written Law seems to be precise in its description of legal codes and commandments, it would be impossible to write down every conceivable human behavior and tell whether or not the Law allowed each one. Concerning the prohibition of work on the Sabbath, for example, we notice that nowhere in the Law is there a definition of what constitutes labor on the Sabbath and what does not. Amos (8.5) and Jeremiah (17.21–24) mention keeping the Sabbath in concrete terms—forbidding trading and bearing a burden—but it is impossible to enumerate all the probable behaviors and circumstances and give judgment as to whether or not they violate the Sabbath. This became more of a problem as time went on and the historical and cultural circumstances changed in later periods. The violation of the Sabbath is a very serious offense for Jewish people everywhere, but the absence of a precise definition of working on the Sabbath in the Pentateuch has been a persistent problem. Unless people have a clear definition of what constitutes labor on the Sabbath, they cannot observe it. Even for contemporary pious Christians, this is a serious problem. Like Amos and Jeremiah, the believing community had their own understanding about the Sabbath, and that became the tradition of the community. Since the time of Ezra in the post-exilic period, many experts on the law (scribes, sopherim) were interpreting the Torah in and for their covenant community, and the community regarded their words as having the same binding authority as the written Law.

The traditional interpretations of the Law by the experts on the law and the great rabbis (particularly after the destruction of Jerusalem in A.D. 70) became the unwritten or oral law. The oral law gained equal footing and took on the same kind of binding authority as the written Law. The function of the oral law is to “make a fence for the Law” (Aboth 1.1). The written Law is to be protected by keeping and observing the tradition (oral law). Jewish people were able not to violate the written Law only by observing the oral law. By obeying the tradition in concrete terms (no business on the Sabbath, for instance), they could observe the commandment about the Sabbath.

In the period of rabbinic Judaism it was believed that God revealed his will not only through the sacred book, that is, the Pentateuch (the written Torah), but through unwritten traditions as well. The rabbis claimed that the oral law, which was transmitted by word of mouth, was also given to Moses at Mount Sinai. It existed side by side along with the written Law ever since. “Moses received the Law (written and unwritten) from Sinai (from God) and transmitted it to Joshua, and Joshua to the elders, and the elders to the prophets, the prophets transmitted it to the men of Great Assembly” (Aboth 1.1). This unwritten Torah was written down and collected in the book called the Talmud. The Mishnah, which was compiled by Rabbi Judah the Prince (born in A.D. 135), is the most important tradition in the Talmud.

We find this phenomenon in other religions as well. Islam has the Hadith and Christianity (Catholic and Orthodox) has the Apostolic traditions. The Protestant churches do not recognize the Apostolic traditions as authoritative as the written Bible, yet they do recognize their importance for theology.

Whether it is the written Law or oral law, “the whole Law is summed up in a single commandment, ‘You shall love your neighbor as yourself,’” as Paul states in his letter to the Galatians (5.14).