1
general::
Deeply wound or distress, as in His criticism cut her to the quick. This phrase uses the quick in the sense of a vital or a very sensitive part of the body, such as under the fingernails. It Also appeared in such older locutions as touched to the quick, for "deeply affected," and stung to the quick, for "wounded, distressed," both dating from the early 1500s. The current expression was considered a cliché from about 1850 on.
American Heritage Idioms
2
general::
Phrase(s): cut someone to the quick [and] cut someone to the bone
1. Lit. to slice the flesh of someone or some animal clear through to the underlying layer of flesh or to the bone. • With the very sharp knife, David cut the beast to the quick in one blow. • He cut his finger to the quick with the sharp knife. 2. Fig. to injure someone emotionally. (See also cut something to the bone.) • Your heartless comments cut me to the quick. • Her remarks cut him to the bone.
McGrawhill's American Idioms And Phrasal Verbs