Genesis 6:20

Of fowls after their kind, and of cattle after their kind, of every creeping thing of the earth after his kind, two of every sort shall come unto thee, to keep them alive.

Cross-reference

In Genesis 1:20-24, God creates birds and land animals by kind — the same categories Noah brings into the ark here.

Genesis 7:8–16 Prophetic fulfillment

Genesis 7:8-16 details the actual entry of animals by pairs and kinds, fulfilling the instruction given here.

Genesis 7:15 Prophetic fulfillment

In Genesis 7:15, pairs of all flesh enter the ark with Noah, directly executing this command.

In Genesis 1:24, God creates land animals by kind — the same kinds Noah brings into the ark here.

In Genesis 2:19, Adam names animals by kind — Noah now gathers them by the same kind-divisions.