What is the reason for and the ruling on the disparity in the number of verses within the quarters (Arba') of the Hizbs in the Noble Qur'an, where the number of verses in some of them reaches 9, while in others it reaches 70-86?

"The division of the Quran into surahs was known during the time of the Companions, and sometimes they estimated by verses. The division into seven ahzab (parts) by surahs is mentioned in a weak hadith, but it aligns with Abdullah ibn Amr's hadith in the two Sahih collections: 'So recite it every seven days, and do not exceed that.' As for the current division by letters, it was introduced during the time of Al-Hajjaj in Iraq, and this is what caused the variation in the number of verses in each hizb."