De Trinitate 5.8.9 (by Augustine of Hippo)--Trinitas and Metaphora

But position, and condition, and places, and times, are not said to be in God properly, but metaphorically and through similitudes. For He is both said to dwell between the cherubims, which is spoken in respect to position; and to be covered with the deep as with a garment, which is said in respect to condition; and Your years shall have no end, which is said in respect of time; and, If I ascend up into heaven, You are there, which is said in respect to place. And as respects action (or making), perhaps it may be said most truly of God alone, for God alone makes and Himself is not made. Nor is He liable to passions as far as belongs to that substance whereby He is God. So the Father is omnipotent, the Son omnipotent, and the Holy Spirit is omnipotent; yet not three omnipotents, but one omnipotent: For of Him are all things, and through Him are all things, and in Him are all things; to whom be glory. Whatever, therefore, is spoken of God in respect to Himself, is both spoken singly of each person, that is, of the Father, and the Son, and the Holy Spirit; and together of the Trinity itself, not plurally but in the singular. For inasmuch as to God it is not one thing to be, and another thing to be great, but to Him it is the same thing to be, as it is to be great; therefore, as we do not say three essences, so we do not say three greatnesses, but one essence and one greatness. I say essence, which in Greek is called οὐσία, and which we call more usually substance.

Source: Translated by Arthur West Haddan. From Nicene and Post-Nicene Fathers, First Series, Vol. 3. Edited by Philip Schaff. (Buffalo, NY: Christian Literature Publishing Co., 1887.) Revised and edited for New Advent by Kevin Knight. .