IN SHORT
I have not the time to read the entire
State (or
Republic) by Plato;
the 1991 Cliffs Notes,
in Book VI, Section 16,
"money or possessions will not matter to him."
MORE
This is a description of the philosopher rulers--the Guardians. Understand that the Guardians are not "kings" in the sense that they are notorious for today. The advantages and disadvantages of Guardians basically cancel each other out, compared to the soldiers, craftsman, etc. The basically is also "covered" by the Myth of the Metals.