I'm studying Genesis 15, in preparation for this Sunday's sermon.
Yet again Bruce Waltke is very helpful.
Here is one paragraph (from pages 239-240). The details he highlights probably won't make it into the sermon, unless they're crucial to the flow of thought in the chapter. But it's important that we see how the promises God makes Abraham in chapter 15 are precisely those that he needed after the events of chapter 14, redefining his protection, his reward and his allies.