Hugh Ross and others of the old-Earth creationist organization Reasons to Believe, who claim to have a literal interpretation of Genesis, believe that Adam and Eve were vegetarian before the Fall (Genesis 1:29), but that carnivorous animals of today were carnivorous then as well. They say that Genesis 1:30:
And to every beast of the earth and to every bird of the heavens 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.
is stating that all of Earth's major ecosystems are based on green plant life, and is not saying that all animals were herbivores.
Is there any historical or linguistic precedent for this interpretation? In other words, did any Jewish or early Christian scholars interpret Genesis 1:30 as anything like this? If so, what linguistic subtleties do they point to that results in a carnivorous interpretation of 1:30, but a non-carnivorous interpretation of the preceding verse?