A statement, usually offered as an excuse for not doing something which may be very important, but which may be done by any one of a number of people. Usually left to do for the person with conscience and perhaps as little time as anyone.
Have you seen this in your workplace or on this wiki?
Well, my manager does it as a polite way to say it is your job to do it.
You call that "polite"? I call it a cold slap in the face with a wet towel.
Then you're possibly too easily offended. Perhaps the intent could be offensive (i.e. "my time is more important than yours, so I will delegate the menial chore to you while I work on more important things"), or perhaps not (it could be "I have to delegate something to somebody; I have chosen to delegate this to you - do not draw any further inferences from this decision"). Depends on the manager and the situation.
Alternate Definition
A statement giving an honest assessment of one's ability to complete a particular task.
I find this statement far superior to the assertion "Yes, I'll do it" followed by inaction. If someone does not have time and informs me, then I can take one of several actions. I can work to eliminate a task of lesser importance, I can assign the task to another who does have time, or I may determine that this task can be deferred in preference to other tasks. One should avoiding playing Superman and taking on more work than one can do. If one is over tasked, say so!
See: NotEnoughTime, CountTheHands