The biblical text, however, is rather easy to understand without giving up on the inspiration of Genesis, or the authorship of Moses: the clean beasts and birds entered the ark "by sevens" (KJV), while the unclean animals went into the ark by twos. There is no contradiction here. Genesis 6:19 indicates that Noah was to take "two of every sort into the ark." Then, four verses later, God supplemented this original instruction, informing Noah in a more detailed manner, to take more of the clean animals. If a farmer told his son to take two of every kind of farm animal to the state fair, and then instructed his son to take several extra chickens and two extra pigs for a barbecue, would anyone accuse the farmer of contradicting himself? Certainly not. It was necessary for Noah to take additional clean animals because, upon his departure from the ark after the Flood, he "built an altar to the Lord, and took of every clean animal and of every clean bird, and offered burnt offerings on the altar" (Genesis 8:20). If Noah had taken only two clean animals from which to choose when sacrificing to God after departing the ark, then he would have driven the various kinds of clean beasts and birds into extinction by sacrificing one of each pair. Thus, after God told Noah to take two of every kind of animal into the ark, He then instructed him to take extras of the clean animals. Similar to how Genesis chapter 2 supplements the first chapter of Genesis by giving a more detailed account of the Creation (see Lyons,2002), the first portion of Genesis 7 merely supplements the end of the preceding chapter, "containing several particulars of a minute description which were not embraced in the general directions first given to Noah" (Jamieson, et al., 1997).