As I was reading this, all kinds of prayers that I've read from the ancient world came to mind, along with the techniques they used. Some obviously magical, some more do ut des, some repetitive—as if to wear the god out until the request was granted—, some full of rhetorical flourishes, and some, especially the from the Psalms, just the pouring out of a heart in distress. And then the admonition by Jesus about vain repetition came to mind.
So what do we do with all these data? I'm still (after 40+ years as a Christian) trying to formulate a theology of prayer. I think the best I can do is, "It's messy, but it works (sometimes)!" What do you think?