The book you are looking for is titled Fiqh al-Lugha wa Sirr al-Arabiya
الثعالبي؛ عبد الملك بن محمد بن إسماعيل، أبو منصور الثعالبي
(d. 429 AH / 1038 AD). It is one of the most significant works in the study of Arabic philology and semantics. Accessing the PDF on Al-Maktaba al-Waqfiyya The phrase "almktbt alwqfyt" refers to Al-Maktaba al-Waqfiyya