1
general::
Phrase(s): come to blows (over someone or something) [and] come to blows (about someone or something)
to reach the point of fighting about someone or something. • Let’s not come to blows over this silly disagreement.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Begin to fight. For example, It hardly seems worth coming to blows over a dollar! Thomas Hobbes had it in Leviathan (1651): "Their controversie must either come to blowes, or be undecided." This term is Also put as fall to blows, especially in Britain. [Late 1500s]
American Heritage Idioms