Typically a-seity is in reference to God’s self causation as it were. As I was at work (sitting on a locomotive) I had some time to reflect upon this depth reality, and once again it continues to be a great source of worship for me.
It blows my mind to ponder the ineffable nature of God; in a healthy way! It caused me great joy to realize that God is greater than my ability to comprehend; it puts me in my creaturely place. As I reflect upon the reality of God in this way it makes me fear him (in a healthy way). It makes me realize how little I am and how gigantic he is. What ultimately blows my mind (to the point of worship) is when I bring this a-se God into view through the Incarnation (or rather as he does this). This ineffable God has become man for me, and for you; because at his very Triune base he is love (his self-Given reality to be eternally for the other within the relations of the God-head). He came just for me and just for you, not because of who I am or who you are, but because of who He is; and this from a God who is a-se and so big that he ultimately goes beyond our capacity to dig any deeper or think any harder.
And so as I was at work and had a moment I had to just sit there and worship.