King James Version (KJV)
11 Thus shall it be done for one bullock, or for one ram, or for a lamb, or a kid.
12 According to the number that ye shall prepare, so shall ye do to every one according to their number.
13 All that are born of the country shall do these things after this manner, in offering an offering made by fire, of a sweet savour unto the Lord.
What I get from this is that no one knows the number, of days of their life. So, prepare for the next day as if you will be here. Yet, many people don't prepare for tomorrow. They say things like, 'Tomorrow is not guaranteed. So, I have fun today.' (Many people make decisions from incomplete information.) The only problem with that saying is; What if you do live to see tomorrow? We know that your actions, today, determines your tomorrow. So, while you are focused on having fun, today, you are creating hardship, for yourself, tomorrow. Unlearn.