「之言」一直被訓詁家公認為探求語源之術語，然經由本文對王念孫《讀書雜志》「之言」術語所作之分析發現，其術語主要作用在於釋義而非探源，因《雜志》本為「隨文釋義」之訓詁專書，對術語之運用自然亦出於訓詁學釋義之觀念。 然而，較諸王氏另一名著《廣雅疏證》 ，其中「之言」術語師可用於釋義、亦可據以推源，探究二者之所以歧異，殆亦由於各書之性質使然。《廣雅》乃「通釋語義」之專著，原本即具多重之屬性，王氏為作《疏證》 ，自亦依其「語義」性質之不同而或探源、或釋義。 最後，本文綜合對《雜志》一系列「因聲求義」術語之解讀，而將其「因聲求義」之法重新定義為:依據聲音之關係以推求文本具體詞義之訓話方法，作用在於釋義，而此亦與其書之性質正相吻合也。

"Zhi Van" has long been considered to be a terminology in the etymological research, yet my study on Wang Nian-sun's "Zhi Van" of Du Shu Za Zhi finds that its terminological function is for interpretation instead of etymological investigation. Since Du Shu Za Zhi is a academic book of Scholium on "Sui Wen Sui Yi" (contextual interpretation), the application of the terminologies is derived from the concept of interpretation in Scholium. However, in Wang's another publication, Guang Ya Shu Zheng, the terminology of "Zhi Yan" refers to erther hermeneutic or etymological investigation. The difference may due to the nature of the books. The latter is an academic work on "general interpretation of semantics" and is imbedded with multiple characteristics. Wang proceeded with etymological investigation and interpretation based on the characteristics of the "semantics" in Guang Ya Shu Zheng. Lastly, this study provided interpretation on "Yin Sheng Qiu Yi" (semantics based on the pronunciation) for Du Shu Za Zhi, and refined the method as: a scholarly method that uses the relationship of the sound to deduce the semantics for the purpose of interpretation. The definition corresponds with the characteristics of the book.