Foreshadowing

I've been reading through Genesis and Exodus lately. I'm thinking of a few connections. First, there is Jacob and Essau. We read that "the older will serve the younger." Jacob takes the birth rights of his brother. Then I read where God says, "Israel is my firstborn." Hmm. Who then is his second born? The gentiles? Then, I also think about the saying, "The first shall be last, and the last shall be first." I'm not going too into depth on this right now, but I am seeing some connections, possibly some foreshadowing. I would love to hear anyone's thoughts on this who would like to look deeper.