‘And God said, “Behold I have given you every plant yielding seed which is upon the face of all the earth, and every tree with seed in its fruit you shall have them for food. And to every beast of the earth, and to every bird of the air, and to everything that creeps on the earth, everything that has the breath of life, I have given every green plant for food”. And it was so.'
God reminds man that He has made full provision for them, providing a storehouse that will propagate itself. Man may eat of the seeds of plants and of fruit. They are God's provision for them, and are provided in abundance for their enjoyment. They will not have to be fought for or toiled for, for they reproduce themselves. These two verses are the purpose to which the whole narrative leads up. They are God's covenant with man around which the context is built.
So the whole narrative is built around this covenant with man in verses Genesis 1:28-30. The whole chapter is the historical background preparing for this covenant in which Man is given his instructions, and has explained to him his purpose and the provision that God has made for him.
Why was there a creation in the first place? It was so that man could be created and could multiply, enjoying the full benefits of God's provision. God has fulfilled His responsibility in making full provision for man and by giving him life. Man's responsibility on the other hand is to watch over the world that God has made.
The suggestion is also here that God's ‘intention' was that the world would progress without bloodshed. Both animals and man could live from the fruit and vegetation of the earth. ‘Nature red in tooth and claw' is therefore seen as an aberration from God's purposes. What caused such a change of situation we are not told, but the strong language of Genesis 1:28 suggests it already has to be contended with when man appears on the scene. The animals need to be ‘subdued', to be tamed. Thus ‘nature' is already getting out of hand. In the ‘ideal' world of the future there would no longer be bloodshed (Isaiah 11:6-9; Isaiah 65:25).
There are differences of viewpoint as to when ‘mankind' became ‘Adam'. The answer is found in when he became a worshipping creature. It was then, whenever that was, that the image of God' was revealed. All viewpoints seem, however, to be agreed that mankind came from a single original pair.