I understand you're looking for a paper or PDF related to the book titled (المبادئ والغايات في معاني الحروف والآيات) by Tha'lab (Tha'lab or Tha'lab al-Nahwi). This is a classical Arabic linguistic and Quranic exegesis work focusing on the meanings of particles (ḥurūf) and verses (āyāt).