Did God Change the Rules After the Flood?

 Rethinking “Every Moving Thing” and the Distinction Between Clean and Unclean Animals Before Sinai

A Change in Diet or a Clarification of Standards?
Many Bible readers assume that God only introduced the concepts of clean and unclean animals at Mount Sinai through Moses. It’s also commonly believed that humanity was vegetarian until after the flood, when God supposedly gave Noah permission to eat animals for the first time. But when we carefully examine the biblical text from Genesis to Exodus, a different picture emerges—one of continuity rather than change.

The account of Noah offers compelling clues that clean and unclean distinctions were already known and practiced long before the giving of the Law. And the often-cited verse in Genesis 9:3 (“Every moving thing that lives shall be food for you”) may not be the sweeping dietary shift it’s assumed to be. The language and context suggest something else entirely: not a divine pivot, but a reiteration of existing allowances.

1. Before the Flood: Were People Eating Meat?

Genesis 1:29 records that God gave Adam and Eve “every herb bearing seed” and “every tree…with seed in it” for food. This has led many to believe that humans were strictly vegetarian prior to the flood. However, the verse simply states what was given; it does not prohibit anything not mentioned. More importantly, it predates the fall, after which human behavior and needs changed dramatically.

In Genesis 4, we meet Abel, a keeper of flocks, who offers “the firstlings of his flock and of the fat thereof” to God (Genesis 4:4). This mirrors later sacrificial instructions in Leviticus (e.g., Leviticus 3:16), where the fat is designated as God’s portion in a meat offering. Abel’s sacrifice suggests a known and accepted use for animals beyond companionship or wool—likely including meat, at least in a sacrificial context.

Additionally, God gave humanity dominion over animals in Genesis 1:28. While “dominion” doesn’t directly imply permission to eat animals, it does involve stewardship that could include their use in life-sustaining ways. The text offers no direct insight into Adam’s diet after Eden, but the existence of flocks and sacrificial systems points toward an understanding of animals as more than ornamental.

2. Clean and Unclean: A Pre-Sinai Understanding

In Genesis 7:2, God instructs Noah to take into the ark seven pairs of every clean animal and one pair of every unclean animal. This instruction makes two things clear:

• The distinction between clean and unclean animals already existed.
  
• Noah understood these categories without needing an explanation.
  

Given the limited space on the ark, it’s unlikely Noah brought extra clean animals solely for reproduction. A more plausible explanation is that clean animals were intended for food and sacrifice. After the flood, Noah offers a burnt offering using “every clean animal and every clean bird” (Genesis 8:20). Not all were used at once, but representatives from each clean category were offered.

This emphasis on clean animals aligns with the later requirements of the Law and shows that these distinctions were not new at Sinai—they were already in place and understood.

3. “Every Moving Thing”: A Closer Look at Genesis 9:3

After the flood, God tells Noah, “Every moving thing that lives shall be food for you; as I gave you the green plant, I give you everything” (Genesis 9:3, ESV). At first glance, this may appear to authorize unrestricted meat consumption. But a closer look tells a different story.

The phrasing echoes Genesis 1:29, where God gave “every green plant” for food—yet clearly, not all plants are edible. Likewise, “every moving thing” likely refers to a category within existing boundaries. The context of clean and unclean animals, already established before this statement, would have naturally shaped Noah’s understanding of what could be eaten.

Some scholars point out that the Hebrew construction in verses 3–4 emphasizes contrast: although animals are given for food, the blood must not be eaten. The focus appears to be less on permitting meat and more on regulating its consumption—specifically, prohibiting blood. This fits with later laws emphasizing that blood represents life (Leviticus 17:11).

In this light, Genesis 9:3 reinforces the idea that eating meat was not new, but that its sacredness—and the symbolism of blood—was being formally acknowledged. This lays theological groundwork that points ultimately to the significance of Christ’s blood as atonement.

4. Sacrifices from Genesis to Exodus: Always Clean Animals

Throughout Genesis, whenever sacrifices are mentioned, they involve clean animals. From Abel to Noah to Abraham and even Jacob, every instance aligns with what would later be codified in the Mosaic Law.

• Genesis 22:13: Abraham offers a ram—a clean animal.
  
• Genesis 46:1: Israel offers sacrifices as he journeys to Egypt.
  
• Exodus 12:3: The Israelites are told to take a lamb without blemish for the Passover—before Sinai.
  

The consistency is striking. God was not introducing new categories at Sinai, but formalizing a standard already understood and practiced. This supports the view that God’s expectations were present from the beginning, even before they were formally codified.

A Continuous Standard, Not a Sudden Shift

The biblical narrative from Genesis to Sinai paints a picture of continuity, not discontinuity. God’s moral and ritual standards didn’t begin with Moses; they were embedded in creation, revealed to the patriarchs, and followed long before Sinai.

Genesis 9:3 is best read not as a blanket license to eat anything that moves, but as a confirmation of God’s provision—with a serious reminder about the sanctity of life represented by blood. The clean and unclean categories, like the sacrificial system, were already part of God’s revealed order.

Rather than viewing the Bible as a sequence of disconnected dispensations, we are invited to see it as a continuous revelation—unfolding the character and will of a God whose laws reflect His unchanging nature.