'Pen is mightier than sword' sources

'The pen is mightier than the sword' is a phrase much in circulation at the moment, and for obvious reasons. Cartoonists offering a visual response to the Charlie Hebdo murders have employed images of pens and pencils, often ingeniously, to support the metonymic proposition that a drawing has greater impact than a bullet.

I was surprisied to learn that the phrase in its modern sense is attributed to Edward Bulwer-Lytton, he of 'dark and stormy night' fame. It appears in his 1839 play Richelieu; Or the Conspiracy:

True, This! —

Beneath the rule of men entirely great

The pen is mightier than the sword. Behold

The arch-enchanters wand! — itself is nothing! —

But taking sorcery from the master-hand

To paralyse the Cæsars, and to strike

The loud earth breathless! — Take away the sword —

States can be saved without it!

Even more surprising are earlier attributions. Euripides is said to be one (although hard to substantiate) and another is the seventh century Assyrian sage Ahiqar (whose version is translated as "The word is mightier than the sword." Am I alone in preferring the punning word/sword form?).  Shakespeare went for the fussy variation of 'rapiers' and 'goose quills' in Hamlet (1600). Then there's the Bible. Hebrews 4:12 (in the King James Version) reads:

For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart.

And finally:

The ink of the scholar is holier than the blood of the martyr.

These are the words of Abū al-Qāsim Muḥammad ibn ʿAbd Allāh ibn ʿAbd al-Muṭṭalib ibn Hāshim (570-632 AD), better known as the prophet Muḥammad.

They seem pretty unambiguous.