Not that man then first began to eat animal flesh, but only that God for the first time authorized, or rather allowed, him to do what the Flood had made a necessity. The wicked antediluvians were flesh eaters (CH 109). But it was not the original will of the Creator that His creatures should consume one another. He had given man plants for food (ch. 1:29). With the temporary destruction of all plant life during the Flood and the exhaustion of the food supplies that were taken into the ark, an emergency arose that God met by giving permission to eat the flesh of animals. Furthermore, the eating of flesh food would shorten men’s sinful lives (CD 373).

 This permission did not imply an unrestrained and unlimited eating of every kind of animal. The phrase, “moving thing that liveth,” clearly excludes the eating of carcasses of animals that had died or been killed by other beasts, which the Mosaic law later specifically forbade (Ex. 22:31; Lev. 22:8). Though the distinction between clean and unclean animals in regard to food is not made here, it does not follow that it was unknown to Noah. That Noah was acquainted with this distinction is clear from the previous command to bring more clean than unclean beasts into the ark (Gen. 7:2), and by the fact that he offered only clean animals as his burnt offering (ch. 8:20).

 This distinction must have been known to early man so well that it was not necessary for God to draw Noah’s special attention to it. It was only when this distinction had been lost through the centuries of man’s estrangement from God that new and written directives were issued regarding clean and unclean animals (see Lev. 11; Deut. 14). The immutability of God’s character (James 1:17) precludes the possibility of construing this passage as permission to slaughter and eat all creatures. Animals that were unclean for one purpose could not have been clean for another.

This implies the newness of the permission to eat flesh food, in addition to the vegetables and fruits that had originally been destined to be man’s food. Not only was the temporary absence of plant life, as a result of the Flood, the reason for God’s permission to man to supplement his vegetarian diet with meat, but probably also the fact that the Flood had so thoroughly changed this earth’s outward form and diminished its fertility that in some lands, such as the far north, it would not produce sufficient vegetarian food to sustain the human race.