what is the verbatim (word for word if possible) translation of the phrase 揚子法言?
揚子 is simply the author's name (originally 揚雄, 子 being a respectful address form analogous to 孔子/孔丘, Confucius).

法言: 言 means speech or word or writings. 法 is a central concept of Confucianism. According to 《爾雅·釋詁》: 法，常也。 It derives from classical ceremonial practices and pertains to social norms and moral philosophy (a bit similar to the Hindu concept of dharma, which is translated as 法 in Chinese). The work itself is thus a disputation on Confucian philosophy.