Sitting on hands - is an idiom of "doing nothing", of "taking no action"... It's negative in meaning: "No matter what happen, I won't do a thing". But...
Let me tell you the 1st story:
I am IT-guy. Yes, that crazy kind of people, that love to sit all the night staring at PC/Mac/whatever..
I work in IT and I meet a lot of people somehow related to IT. IT is a fast-business thing. Things change fast, new things appear, some disappear. To be good in IT - you need to adapt ASAP to the changes. And so, IT people are often realy fast in what they are doing...
Let's imagine that boss tells you about his new brilliant idea. Or just you read about a new software development technique... The thing is simple, looks like easy to make, so most IT guys don't even let the boss finish talking about the idea. They don't let complete the DESIGN. They start working.
They start, they do, they implement/code/test/program/whatever... And - it often DOES NOT WORK. It has bugs, it is slow, it needs to be rewritten. How many times we can hear, the IT guy needs to redo something.
Why?
My opinion: between "The Idea", and "The Do It" - there is a gap. People don't care about it, because most of them assume that's a waste of time. The gap is called "The Design" or "The Architecture" or it may be called a thousand of other names.
Anyway - that's my "Sit on your hands" definition: THINK before you DO.
