What is the wisdom behind the word "at-tabattul" appearing only in Surat al-Muzammil?

The occurrence of a word only once in the Qur’an does not necessarily imply a specific secret, as many words are not repeated within it. As for the word "al-tabattul," it did not appear in the Qur’an; rather, the word "al-tabteel" appeared instead. This might be due to maintaining consistency in the breaks between verses. Both terms are derived from the root "batala," which means to cut. In the Arabic language, one verbal noun often substitutes for another, and examples of this in the Qur’an include: {إِلَّا أَنْ تَتَّقُوا مِنْهُمْ تُقَاةً} (unless you fear from them a [due] precaution) and {وَاللَّهُ أَنْبَتَكُمْ مِنَ الْأَرْضِ نَبَاتاً} (And Allah has caused you to grow from the earth a [progressive] growth).