What is Huang Po's Mind?

I've tried to look up answers, but they're all just obscurantist discussions with no real content I can discern. So I wanted to ask here. What is Huang Po's Mind? Is it some mind field common to all sentient beings, which each one is an expression of? Is it just a poetic way of talking about one's own mind? Is it a conscious or cognitive ground of being?

(Please don't answer with the common "don't conceptualize, just sit and meditate" answers that one usually gets in this community. :-P That's not what I am looking for. I am already meditating and trying to experience for myself and so on. Right now I am interested in what Huang Po meant by his Mind.)