Keep Hans Wehr’s Dictionary of Modern Written Arabic or the Lisan al-‘Arab (online) open. Al-Kashani often uses words in a technical sense distinct from common Arabic.
Check the introduction of the PDF to see if the publisher attributes the text to Abd al-Razzaj al-Kashani (the Sufi master) or Fayd al-Kashani (author of Al-Safi and Al-Asfi ), as this will help you contextualize the commentary style. Conclusion tafsir al-kashani part 2 pdf
If you are looking to deepen your study of this text, let me know: Keep Hans Wehr’s Dictionary of Modern Written Arabic