Noach was the past, Avrahom the future

This is an extension of my post Difference between תולדות אדם and תולדות שם. When looking at תולדות אדם we see that it starts with אדם and ends with Noach and the birth of his three sons. On the other hand, the build up to אברהם starts at Shem and ends with Terach and the birth of אברם נחור והרן as well as the birth of their children. Similarly, when נח dies, he is spoken of in the exact way that the rest of the people listed in תולדות האדם. Avraham on the other hand, begins the complete beginning of the narrative and is never linked to the previous generations. In fact, the first we hear of him is to be told how he had to leave and separate himself from all that went before. The Torah shows this by the names of the Parshios as well as the name of the people involved. נח  means rest, staying the same and is the end of the progression that takes the world past the mabul. לך לך means movement, separation and going to the future. Similarly, אברהם is given the nam אב המון גוים which means that he is the beginning of the future and the start of the next phase of history rather than the end of the previous stage.

When did Avraham perform Bris Milah?

Rabbi Monk in קול התורה says that the use of the term בעצם היום הזה actually means that it took place on Yom Kippur. This connects the blood of the bris with the korbonos of Yom Kippur and allows for some interesting drashos. However, this means that the Malachim had to have come on the 12th of Tishrei (the third day). We have learned that Sarah conceived on Rosh Hashannah following the bris and Yitzchak was born on Pesach after a seven month pregnancy (this includes an Adar Sheni that year).

This means that it took about a year and a half from the bris until Yitzchak was born. This means that Avraham turned 100 after the following Pesach and before the following Yom Kippur, since he was 99 at the time of the Bris. This means that the interpretation of כעת חיה as "this time next year", means that they said that when the sun reaches a particular point in its orbit "next year" (after the following Rosh Hashanah, Yitzchak will be born. Alternatively, it could mean "in the normal course of events" without being a specific time.

On the other hand, those who say that the malachim came on Pesach (like Rashi) follow the interpretation of Rav Shamson Rafael Hirsch, that בעצם היום הזה means in broad daylight and as soon as he was commanded. In this interpretation, Avraham could have just turned 99 or could have been 99 for a while. There is no way that we can logically determine what month he was born in from this part of the Torah. In this case, Yitzchak was born precisely a year later.

Why Hashem did not leave Mishpatim up to us

Rabbi Sacks posted an interesting article on Noach – True Morality which actually helps explain why Hashem had the Torah command us in the area of Mishpatim as well as Chukim. Mishpatim are usually translated as "rational" laws. That is, the laws that people should be able to determine for themselves that they are needed, such as theft and murder.

Rabbi Sacks points that that modern Games Theory and some neo-Darwinist analyses are finally explaining the rational basis for morality. The article points out that there is actually a rational basis for unselfishness and that a community is more likely to survive than a group of ruthless and completely selfish individuals. It took until now for people to come up with the logical and rational explanation. That is why Hashem had to give us the "logical laws" as commandments in the Torah. If he had not, we were likely to not come up with them on our own (the generation of the Flood is an example of such a society).

As Rabbi Sacks wrote:

In one of the first great works of Jewish philosophy – Sefer Emunot ve-Deot (The Book of Beliefs and Opinions) – R. Saadia Gaon (882-942) explained that the truths of the Torah could be established by reason. Why then was revelation necessary? Because it takes humanity time to arrive at truth, and there are many slips and pitfalls along the way. It took more than a thousand years after R. Saadia Gaon for humanity to demonstrate the fundamental moral truths that lie at the basis of G-d’s covenant with humankind: that co-operation is as necessary as competition, that co-operation depends on trust, that trust requires justice, and that justice itself is incomplete without forgiveness. Morality is not simply what we choose it to be. It is part of the basic fabric of the universe, revealed to us by the universe’s Creator, long ago.