Well, almost. In order to have permission from an author to copy or distribute a GPL licensed work, I have only the GPL to look to as a source for such a permission. The GPL states that I have to choose one of a number of options; if I choose none of them, I can’t distribute, because copyright law states that only the authors have that right, unless they give permission. The available options are listed in section 3 of GPL 2. The first option is to simply always send the source code with every copy of the program; as in, include the source code in the app or binary sent to every user of the program. The second option is to include a “written offer” for source code to every recipient of the app or binary, so that anyone in possession of this offer can take me up on it and have me send them the source code upon request. Note that the person using the offer can be anyone, not just the original recipient of it. The third option is only available if I myself received such a written offer – I can then choose to simply forward this offer on to you instead of making my own. Note that this third option is also only available for non-commercial distribution.
If you got a GPL licensed program from me, and I did not choose any of the three above options, I have violated the GPL and consequently violated the copyright of the original author. You don't have to write me and ask for the source code and be refused in order to know this: If I’m distributing commercially, I can’t use the third option; if you didn’t either get the source code on the disk or in the downloaded archive or had it available on the site for download where you got your app or binary, then I didn’t choose the first option; if you can’t find a written offer from me anywhere, then I didn’t choose the second option.