look at the verses:
Gen 1:29 Then God said, "Behold, I have given you every plant yielding seed that is on the surface of all the earth, and every tree which has fruit yielding seed; it shall be food for you;
Gen 1:30 and to every beast of the earth and to every bird of the sky and to every thing that moves on the earth which has life, {I have given} every green plant for food"; and it was so.
what you have is the same literary structure repeated throughout chapter 1. typical Hebrew poetical structure see:
http://www.jewishencyclopedia.com/view.jsp?artid=67&letter=P
for a nice discussion of parallelism.
pair a/b
God has dominion/creates
God gives life to mankind/puts him into subordinate position
the big picture is Creation/Providence the great pair of the almighty acts of God.
Man has dominion over animals/animals have dominion over plants
part of the great motif of Gen 1 where God creates the kingdoms and then populates them, finally putting someone/somethings in charge.
with the crescendo being that God is in charge because He created all things.
the crucial element is simply that it doesn't say, God gives only vegetables to man to eat, God gives only green things to the animals to eat. It is a providential ordering of the world. The world is not accidental or a mistake (the common notion in ANE) but rather is a deliberate act of God's sovereign will to create and to sustain the universe.
again you are reading into the Scriptures things which simply are not there.
simply put. it is analogous to those pesky IQ tests:
square is to circle as ace of hearts is to ------.
to find support for human vegetarianism in those is esegesis let alone something as radical as all creatures were vegetarians until the fall.
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