A. This is not a matter of whether to fill or empty, but a matter of realising what the mind is. The ultimate end of Zen meditation is to realise what the mind that you are going to fill or empty is.
This question shows well how unaware we are of what we say and how imprudently we are seeking happiness. How could we fill or empty the mind while not knowing what it is? In fact, it is because you don’t know what your mind is that you have such an idea of filling or emptying it. Once you get to see it clearly, you will realise that it can’t be filled or emptied because it is perfect, and that you are happiness itself.
All writing ©Boo Ahm. All images ©Simon Hathaway