Abraham Goes on a Circumcision Spree (Genesis 15-18)

I feel like I should just skip ahead to the part about circumcision. But a bit of background first: God is really liking Abraham and he gives him a large tract of land from the river of Egypt (the Nile?) to the river Euphrates. He also makes a covenant with Abraham. What are the rules of making covenants exactly? Are they like the rules of dating? Now that Noah's dead, I guess it's okay that God makes a covenant with Abraham; otherwise, I feel like it would be cheating in a way.

A covenant is all well and good but Abraham still has the problem of a barren wife. Sarah can't cough up an infant so she suggests that he impregnate her servant woman, Hagar (known as the Horrible because of her ungainly looks). Good idea! Abraham needs little convincing and he promptly knocks up Hagar, who gets pretty pissy about the whole situation. Imagine that. Sarah "deal[s] harshly with her," which certainly implies a bitch-slap or two (Gen 16:6). Hagar gives birth to a son, Ishmael, a "wild ass of a man" (Gen 16:12). Say no more. Ishmael doesn't pass muster so God decides that he'll make Sarah pregnant after all. The Bible makes it out to be a big deal because she's ninety, but I thought that everyone lived many hundreds of years anyways. I'm confused. You would think that living that long would buy them a few more procreative years, but apparently not.

There's a catch: God is willing to give Abraham a proper son but he is very intent all of a sudden that all the males get circumcised. He hammers home its importance: "Any uncircumcised male who is not circumcised in the flesh of his foreskin shall be cut off from his people; he has broken my convenant" (Gen 17:14). THAT'S what breaks the convenant with God? Not murder or rape? Got it. So Abraham goes a'circumcisin'. Like crazy. Everybody gets circumcised, even the slaves. All the males were probably in a huge line like they were waiting to buy tickets to Aerosmith. Abraham gets circumcised, too, at ninety-nine years of age (and it is unclear as to whether or not he circumcises himself). I can't imagine he had a steady hand being that old. Because of all this slicing and dicing, Sarah bears him a son, Isaac.