In Genesis 7:2, Noah is told to take seven pairs of every clean animal onto the Ark. The same instruction says to take one pair of animals that were not clean.
The passage distinguishes between clean and unclean animals before the Israelite dietary laws are formally presented elsewhere in the Hebrew Bible. Genesis does not provide a complete species-by-species list in the Ark narrative, so the category is not defined there in modern zoological terms.
Some English translations phrase the instruction as “seven” of each clean animal rather than “seven pairs.” This reflects a Hebrew wording that has been translated in different ways, and it creates an important textual variation. The traditional “seven pairs” wording is nevertheless a familiar rendering of Genesis 7:2.
This detail is often simplified into “two of every animal,” but Genesis gives a more differentiated account for clean and unclean animals.