In Genesis’s account of Noah’s Ark, Noah took seven pairs of each clean animal aboard.
Genesis 7:2 distinguishes clean animals from animals that were not clean. Noah is instructed to take seven pairs of clean animals, but only one pair of animals that were not clean. Genesis 7:3 separately mentions seven pairs of birds.
The clean-animal instruction is often remembered incorrectly as two of every animal. That shorter formula appears in Genesis 6:19–20, where God tells Noah to bring a male and female of every kind. The later passage adds the special number for clean animals.
The distinction may relate to later Israelite dietary and sacrificial categories, although Genesis does not provide a complete classification system here. After the Flood, Noah builds an altar and sacrifices some clean animals and birds, making the larger number practically significant in the narrative.