and turned a stubborn shoulder

Exo4 applies like everywhere (and actually begins halfway through Exo3). Interesting dynamic twixt Moses and God. Broken down it looks like this:

* God calls Moses; Moses meets God
* God gives Moses a mission, a calling; Moses asks for clarification
* God clarifies and promises a blessing; Moses throws up a weak reason for turning away
* God gives him not only one support, but three; Moses asks for someone else to do it
* God, burning, gives him Aaron; Moses finally accepts his calling
* God mentions one last thing -- the task will be hardened against him

Perfect analogy of the calling of all Christians, I suppose. Won't be delving further here; too obvious.