Summa contra Gentiles2.11 Chapter XI. That something is said of God in relation to creatures

Now as power is becoming to God in relation to His effects, and as power conveys the notion of a principle, as we have stated;' and since principle denotes relationship to that which proceeds from it, it is evident that something can be said of God relatively, in relation to His effects.

Again. It is inconceivable that one thing be referred to another, unless conversely the latter be referred to it. Now, we speak of other things in relation to God; for example as regards their being which they have from God, as already proved, they are dependent upon Him. Therefore conversely we may speak of God in relation to creatures.

Further. Likeness is a kind of relation. Now God, even as other agents, produces something like Himself. Therefore something is said of Him relatively.

Moreover. Knowledge denotes relation to the thing known. Now God has knowledge not only of Himself, but also of other things. Therefore something is said of God in relation to other things.

Again. Mover implies relation to thing moved, and agent to thing done. Now God is an agent, and an unmoved mover, as already proved. Therefore relations are predicated of Him.

Again. First implies some kind of relation, and so does supreme. Now it was proved in the First Book that He is the first being and the supreme good.

It is therefore evident that many things are said of God relatively.