en_tn/gen/01/22.md

blessed them

"blessed the animals that he had made"

Be fruitful and multiply

This is God's blessing. He told the sea animals to produce more sea animals like themselves, so that there would be many of them in the seas. The word "multiply" explains how they are to be "fruitful." (See: rc://en/ta/man/translate/figs-doublet and rc://en/ta/man/translate/figs-idiom)

multiply

increase greatly in number

Let birds multiply

This is a command. By commanding that birds should multiply, God made birds multiply. (See: rc://en/ta/man/translate/figs-imperative)

birds

"animals that fly" or "flying things." See how you translated this in Genesis 1:20.