"I am an angel of the Lord and I mean you no harm," he said bluntly. "If you wish to find your wife, I suggest you refrain from attacking me, you will only damage yourself."
In the past, he wouldn't have become irritated by this part. Castiel was usually met with some sort of resistance regarding what he was, but that level of belief, or lack thereof was exactly why his Father was a failure.
"I am not your enemy."
And he was in something of a rush. Meg could be...easily displeased and then he had no desire to listen to her.