Even better is being told to commit by the Scrum Jesus (who does not even try to understand the business domain or engineering issues, since he's getting hired for being the Scrum Jesus) to stories with no one available for even defining or discussing them. Our story might have been just a word someone saw at a trade fair.
Then, two weeks later, being asked why I did not complete what I committed to.
In that situation I've gotten a lot of mileage (and quiet amusement) from pointing out that Scrum dropped the term "commitment" for "forecast" in 2011. Scrum Jesus has no defense against Scrum itself!
"Development Teams do not commit to completing the work planned during a Sprint Planning Meeting. The Development Team creates a forecast of work it believes will be done, but that forecast will change as more becomes known throughout the Sprint."
Then, two weeks later, being asked why I did not complete what I committed to.