In Genesis, Noah was told to take seven pairs of every clean kind of animal onto the Ark.
Genesis 7:2 distinguishes between clean and unclean animals. It instructs Noah to take seven pairs, described in some translations as seven male-and-female pairs, of clean animals, but only one pair of animals considered unclean. Genesis 7:3 gives a related instruction for birds.
This detail is often simplified to “two of every animal,” because Genesis 6:19–20 describes Noah bringing male-and-female pairs of living creatures. The later instruction adds the clean-animal distinction, creating a textual detail that readers frequently overlook.
The passage does not provide a modern taxonomic list or explain how ancient categories map onto today’s species classification. “Clean” and “unclean” are ritual categories in the biblical text, not a modern zoological system.