Which is the largest Rub’ al-Hizb in the Qur’an?

The division of the Holy Quran into quarters (arbāʿ), hizbs, and juz’s is an interpretive effort (ijtihādī) and not a divine revelation (tawqīfī). It varies from one Mus'haf to another. The quarters were introduced to determine the amount to be memorized or reviewed, and they are not linked to the beginning or end of a Surah. Often, a quarter in commonly used Mus'hafs ranges from two to three pages, and sometimes it may be more or less. Examples of long quarters include the quarter of "The Day when Allah will assemble the Messengers," and examples of short quarters include the quarter of "Whatever is in the heavens and whatever is on the earth glorifies Allah." The deviation of increase or decrease from the usual affects the balance between the quarters. Some have called for their adjustment to be more balanced, as they are a product of ijtihād aimed at serving the memorizer.