its collective form functions like a single entity distinct from other things. This is because the ruling regarding a single unit of it individually is rarely found, so its collective form functioned like a single entity distinct from other things. Then a single unit of it was treated as a piece cut from the whole of it, so it was said: burrah (a grain of wheat), shaʿīrah (a grain of barley), and qaṣabah (a stalk of reed), meaning a piece of it. But the sūrahs of the Qur'an were not present gathered together in the manner of the gathering of wheat, barley, and the wall (sūr) of a city; rather, every sūrah among them exists individually on its own, just as every upper room (ghurfah) among upper rooms (ghuraf) and every sermon (khuṭbah) among sermons (khuṭab) exists individually. Thus, their plural was formed like the plural of ghuraf and khuṭab, whose plurals are built from their singular forms.

And among the evidence that the meaning of sūrah is 'a rank of elevation' is the statement of al-Nābigha of Banū Dhubyān:

Do you not see that God has granted you a high rank (sūrah), Below which you see every king faltering?

He means by that: that God gave him a status among the statuses of honor, compared to which the statuses of kings fell short.

And some of them pronounced sūrah of the Qur'an with a glottal stop (hamza, as su'rah). Its interpretation, in the language of those who pronounce it with a hamza, is a portion that has been left over and retained from the rest of the Qur'an. That is because the su'r of anything is the remainder of it that stays behind after what has been taken from it. For this reason, the leftover of a man's drink—when he drinks it and then leaves some remaining in the vessel—is called su'r. Of that is the statement of Aʿshā Banī Thaʿlaba, describing a woman who parted from him, leaving behind in his heart a remnant of grief for her:

So she departed, having left behind in the heart A fissure, despite her distance, spreading far and wide.