Definition and Purpose
In Jewish tradition, an oath is a solemn promise or declaration, often invoking God as a witness to the truth of one's words or the sincerity of one's intentions. Oaths serve to affirm truthfulness, establish trust, and bind individuals to their commitments. They are considered sacred and binding, reflecting the seriousness with which words and promises are regarded in the biblical context.

Biblical Foundations
The concept of oaths is deeply rooted in the Hebrew Scriptures. The Torah provides several instances where oaths are made and regulated. In Leviticus 19:12, the Israelites are commanded, "You must not swear falsely by My name and so profane the name of your God. I am the LORD." This underscores the gravity of invoking God's name in an oath, emphasizing the need for truthfulness and integrity.

In Numbers 30:2, the importance of fulfilling vows and oaths is highlighted: "If a man makes a vow to the LORD or swears an oath to bind himself with a pledge, he must not break his word; he must do everything he has promised." This passage reflects the binding nature of oaths and the expectation that they be honored.

Types of Oaths
Oaths in Jewish tradition can be categorized into several types:

1. Assertory Oaths: These are declarations of truth regarding past or present facts. An example is found in Genesis 21:23, where Abraham swears to Abimelech that he will not deal falsely with him.

2. Promissory Oaths: These involve commitments to future actions. An example is Jacob's vow to God in Genesis 28:20-22, where he promises to serve God if he returns safely to his father's house.

3. Judicial Oaths: Used in legal contexts to ascertain truth, as seen in Exodus 22:10-11, where an oath is required to resolve disputes over property.

Regulations and Restrictions
The Jewish tradition places significant restrictions on the use of oaths to prevent their misuse. The Third Commandment, "You shall not take the name of the LORD your God in vain" (Exodus 20:7), serves as a foundational principle against frivolous or deceitful oaths. The Mishnah, a key text in Jewish oral law, further elaborates on the conditions and limitations of oaths, emphasizing the need for caution and reverence.

Jesus' Teaching on Oaths
In the New Testament, Jesus addresses the issue of oaths in the Sermon on the Mount. In Matthew 5:33-37 , He teaches, "Again, you have heard that it was said to the ancients, 'Do not break your oath, but fulfill your vows to the Lord.' But I tell you not to swear at all: either by heaven, for it is God’s throne; or by the earth, for it is His footstool; or by Jerusalem, for it is the city of the great King. Nor should you swear by your head, for you cannot make a single hair white or black. Simply let your 'Yes' be 'Yes,' and your 'No,' 'No.' Anything more comes from the evil one." Jesus emphasizes the importance of honesty and integrity without the need for oaths, suggesting that one's word should be sufficient.

Cultural and Religious Significance
Oaths have played a significant role in Jewish culture and religious practice, serving as a means of establishing trust and accountability. They are seen as a reflection of one's relationship with God and others, highlighting the ethical and moral dimensions of speech and promise-keeping. The reverence for oaths in Jewish tradition underscores the broader biblical theme of truthfulness and the sanctity of one's word.