Authors:

Every ruler must remember three things. Firstly, that he rules man; secondly, that he rules according to law, and thirdly, that he does not rule for ever.

Men, Law, Doe
"Dictionary of quotations (classical)". Book by Thomas Benfield Harbottle, p. 515, Stobaeus, Florilegium, XL, VI, 24, 1897.
Every ruler must remember three things. Firstly, that he rules man; secondly, that he rules according to law, and thirdly, that he does not rule for ever.