In Genesis, what animal group was Noah told to take by sevens into the Ark?

Genesis tells Noah to take clean animals by sevens into the Ark.

Genesis 7:2 distinguishes between clean and unclean animals. Noah is instructed to take seven pairs, or seven of each, of clean animals, while taking one pair of each unclean animal. The passage also separately mentions birds, which are to be taken by sevens. English translations differ over whether the wording means seven pairs or seven individuals, but the category named in the question is unambiguous: clean animals.

This instruction appears after Genesis 6:19–20, where the story gives the broader command to preserve male-and-female pairs of living creatures. The two passages are often read together, and the later distinction adds extra clean animals for the post-Flood sacrifice described in Genesis 8.

The term “clean” is a ritual classification in the biblical narrative, not a claim that some animals were physically cleaner. The detailed dietary categories associated with clean and unclean animals are developed elsewhere in the Hebrew Bible, especially Leviticus.