Do right and fear no man, don't write and fear no woman

Any ideas on the origin of "Do right and fear no man, don't write and fear no woman"?

It is sometimes attributed to Mark Twain, but I have doubts. SS

The first half has been traced back to about 1450 in the form 'The beste wysdom that I Can, Ys to doe well, and drede no man'. According to Burton Stevenson's "Home Book of Proverbs" it was the columnist Luke McLuke (J S Hastings) who first said 'Do right and fear no man, don't write and fear no woman'. This, apparently, he wrote in the Cincinatti Enquirer around 1918.