Sounds a little like 'The Simplicity of God' article in the Summa.

God has no parts nor separations within Himself. He is One. I like the name for God in Korean: 하나님

One: 하나 [hana]

"Sir" or suffix for profession: 님 [nim]

This is somewhat to say that God is "The One," prime, the first, and He Whose profession is oneness and to be one.