Genesis 7:15

And they went in unto Noah into the ark, two and two of all flesh, wherein is the breath of life.

Cross-reference

Genesis 6:20 commands two of each kind to come into the ark — here that command is fulfilled as they enter.

Genesis 6:17 announces the flood to destroy all flesh — contrasting with the preservation of animals entering the ark here.

Genesis 6:19 commands bringing two of every sort into the ark — here that command is carried out as they enter.

Genesis 8:17 commands the animals to leave the ark — the reverse of their entry here, completing the flood narrative.