I have previously described the two-fold nature of God’s efficient freedom.
Now God’s matter is simple which means in part that it cannot be divided into component parts. To say that God’s 1st level is free is to pose a further question, “Free to do what?”
A particle of abstract prime matter cannot be divided into parts, either. And neither can it, on its own, without being put under some natural law (and hence under some form), be combined with anything else. Such a particle, in other words, is completely inert.
On the other hand, God’s matter is similar to prime matter (or, more practically, an electron) in being indivisible, but is completely unlike prime matter in that it is permitted, of its own essence and ability, to combine with anything in any way whatsoever.
It is therefore perfectly suited to be united with the soul of God which will determine at its pleasure the need for and manner of any such combination.
Of course, divine matter is fully convertible to energy, and I have suggested that vacuum zero-point energy is an aspect of God’s omnipresence and cause of the Big Bang.
This shows incidentally that God on the 1st level is not prime matter, which is why the Church teaches correctly that God did not create us out of Himself but needed to create prime energy / matter separate from Him before embarking on the rest of His work.
This is God’s internal 1st-level freedom. As before, God’s external 2nd-level freedom means a complete absence of obstacles or restrictions on God’s “pursuit” and enjoyment of happiness.