How did Noah know which animals were clean? When God first commanded Noah, He told him the following:
And of every living thing of all flesh, you shall bring two of every kind into the ark, to keep them alive with you; they shall be male and female. "Of the birds after their kind, and of the animals after their kind, of every creeping thing of the ground after its kind, two of every kind will come to you to keep them alive. (Genesis 6:19-20)About 120 years later, just before Noah was about to enter the ark, God repeated the command, adding in a few additional details:
You shall take with you of every clean animal by sevens, a male and his female; and of the animals that are not clean two, a male and his female; also of the birds of the sky, by sevens, male and female, to keep offspring alive on the face of all the earth. (Genesis 7:2-3)This much is clear: Noah knew which animals were clean. However, Scripture does not clearly indicate how Noah came to know which animals were clean and which animals were unclean. In fact, Genesis 7:2 is the first passage in Scripture to make a distinction between clean and unclean animals.
At the creation of the world, such a distinction between clean and unclean animals did not exist. Genesis 1:31 states that after creation God saw all that He had made, and behold, it was very good. From this, it can be concluded that it was not until after the fall of man that certain animals were marked as clean or unclean.
Typically, the first thought which comes to mind when an animal is called "clean" or unclean" is that some sort of dietary distinction is being made. This, however, does not appear to be the case in this passage. Scripture seems to indicate that before the flood, people did not eat meat; thus the clean and unclean animals of Noah's day were not separated into different categories for dietary reasons (for more information on the food of the pre-flood world see: Genesis 6:21).
How Did Noah Know Which Animals Were Clean? (Part 2) - Genesis 7:2-3
The Time Comes to Enter the Ark (Part 1) - Genesis 7:1
State Of The World (2469 BC): 120 Years Before The Flood - Genesis 6:3
God's Covenant With Noah: Promised - Genesis 6:18
Summary of Genesis 6