The Abhidhamma Pitaka is part of the Pali Canon, first formalised at the Third Council. Tradition has it that it was taught by the Buddha to his mother in Tusita Heaven.
There are many commentaries based on the Abhidhamma. The most common one used by Abhidhamma practitioners nowadays seems to be Abhidhammattha Sangaha by Acariya Anuruddha, translated by Ven. Narada as "A Manual of Abhidhamma" and fleshed out further by Bhikkhu Bodhi to form "A Comprehensive Manual of Abhidhamma".
"Do not force others, including children, by any means whatsoever, to adopt your views, whether by authority, threat, money, propaganda, or even education." - Ven. Thich Nhat Hanh
"The uprooting of identity is seen by the noble ones as pleasurable; but this contradicts what the whole world sees." (Snp 3.12)
"To argue with a person who has renounced the use of reason is like administering medicine to the dead" - Thomas Paine