illustration (attribution, if any possible, is at the end of the article)
From the Aṣṭasāhasrikā sūtra (or "Perfection of Wisdom in 8,000 lines"), many extended and summarised versions arose: from the "Perfection of Wisdom in 100,000 lines" to the Heart sūtra and the Diamond cutter sūtra.
In the Tibetan Canon, there is a "Perfection of Wisdom in one letter", in which the letter a (ཨ) is said to represent the epitome of all the Prajñā literature.
Used as a prefix in Sanskrit, the first letter अ of the alphabet negates the meaning of the word which follows it: svabhāva (with essence) becomes asvabhāva (without essence)… or vidyā (knowledge) becomes avidyā (ignorance). The Tibetan first letter, ཨ, is used similarly.
This is extremely close to the "not have; without" meaning of mu (無) (found in e.g. the mu koan, or the Heart sūtra in Chinese).
No essence, no permanence…
The negation of what one knows,
including the negation of the negation itself…
No clinging, no certainty…
Not knowing, no suffering!
« People cleave to their worldly possessions and selfish passions so blindly as to sacrifice their own lives for them. They are like a child who tries to eat a little honey smeared on the edge of a knife. »
("Sutra in forty-two sections")