In Judaism, there are various laws that determine what foods can and cannot be eaten, as well as how those foods are to be prepared. Collectively these laws are referred to as the “kosher dietary laws,” or sometimes just “kosher laws.” The word kosher is derived from the Hebrew word kasher, which simply means “proper” or “fitting” (see Esther 8:5). Foods that are considered kosher, then, are considered fit or proper for eating.
The basis for the kosher dietary laws is found in the Torah (the first five books of the Old Testament) and are typically split into two major categories: foods that can be eaten and foods that cannot be eaten. The kosher dietary laws are specific to animal-based foods such as mammals, birds, fish, and insects. All plant-based foods are considered kosher by Jews and may be consumed: fruits, vegetables, and grains are allowed.
Most of the kosher dietary laws can be found in Leviticus 11 and Deuteronomy 14. In these passages, God lists which animals the Israelites were allowed to eat (referred to as “clean”) and which ones they were not allowed to eat (referred to as “unclean”). The animals are further divided into four major categories:
Modern Jews will sometimes further divide the kosher dietary laws into more specific rules. For example, some Jews do not consider it kosher to drink milk and eat poultry at the same time—the foods must be separate. However, these more specific rules are not found in the Bible. They usually derive from rabbinic writings much later in history.
In addition to the laws about what foods may be consumed, the kosher dietary laws also specify how those foods are to be prepared. For example, an Israelite could only eat a clean animal if he intentionally slaughtered it for consumption. An animal found already dead (by disease or killed by another animal) was not to be eaten (Leviticus 17:15–16; Deuteronomy 14:21). Israelites were also not allowed to eat the fat of cattle, sheep, or goats, though it could be used for other purposes (Leviticus 7:22–25).
Other kosher dietary laws regarding food preparation include
The details of the kosher dietary laws are comprehensive and can be complex, especially when one considers the oral tradition added to the biblical texts by rabbis. But the passages dealt with above give a good understanding and starting point for what God had commanded the Israelites regarding clean (“kosher”) foods under the Old Covenant.
In Mark 7:17–23, Jesus teaches that what goes into a person does not defile him, but rather the evil thoughts of the heart that come out. Mark 7:19 says, “In saying this, Jesus declared all foods clean.” By fulfilling the Mosaic Law (Matthew 5:17), Jesus freed us from adherence to the kosher dietary laws. We are free to eat whatever food we want, as no food is considered unclean—all foods are now considered “kosher.”
At the same time, God’s Word commands us to glorify God with our bodies because they are temples where the Holy Spirit dwells (1 Corinthians 6:19–20). While all foods are considered clean and we are free to eat whatever we want, we should be careful not to be gluttonous or to eat unhealthily. Excessive eating or unwise diets are not a faithful way to live out the freedom we have in Christ.