Al-Furuq fi al-Lughah - Abu Hilal al-Askari

This is a wonderful dictionary of the nuances between words.

This book is one of the most comprehensive books on linguistic differences, as it includes a presentation of many opinions and explanations that indicate the abundance and mastery of its author and the accuracy of his thinking. The study of these differences came in the light of the Noble Qur’an and the words of the jurists, theologians and other people’s conversations. The author’s goal in this book was to preserve the Arabic language from interpretation, distortion and error, keeping it away from conjugation and idle talk.