This is a blessing from God, although it's not like an IF-THEN statement. It's unconditional, based solely on the goodness of God Himself. Some people think of this as the first of several covenants with men. Scofield writes,
The Edenic Covenant, the first of the eight great covenants of Scripture which condition life and salvation, and about which all Scripture crystallizes, has seven elements. The man and woman in Eden were responsible:
(1) To replenish the earth with a new order - man;
(2) to subdue the earth to human uses;
(3) to have dominion over the animal creation;
(4) to eat herbs and fruits;
(5) to till and keep the garden;
(6) to abstain from eating of the tree of knowledge of good and evil;
(7) the penalty - death.
While I don't think of this as an "Edenic Covenant", the first four elements are certainly true (see the next two verses). The remaining three elements are found the the next chapter, which is why I don't think of it as a part of a covenant. Instead, I find this to be the chief end of man: not to glorify God, as many claim, but to do what God intended from the beginning - Be fruitful, and multiply, and replenish the earth, and subdue it!
