Tafsir of An-Najm 53:50

That is, the ancients, for they were the first of the nations to be destroyed after the people of Noah, as was stated by Ibn Zayd and the majority. Al-Tabari said: It was described as "the first" because there is another ‘Aad among the tribes, which was a tribe that existed in Mecca along with the Amalekites, and they were the descendants of Laqeem ibn Hazal. Al-Mubarrad said: The "other ‘Aad" is Thamud. It has also been said: They are the tyrants (al-Jabbarun). It is further said: The first ‘Aad are the offspring of ‘Aad ibn Iram ibn ‘Awf ibn Sam ibn Noah, and the other ‘Aad are from the descendants of the first ‘Aad. In al-Kashshaf: "The first" are the people of Hud, and "the other" is Iram. And Allah the Exalted knows best.

It is permissible that "the first" refers to those who preceded in honor and status. A group read it as ‘Aad al-Wula (عاد الولي) by eliding the hamza and transferring its damma to the lam before it. Nafi‘ and Abu ‘Amr read it as ‘Aad al-Wulla (عاد الولى) by assimilating the lam to which the vowel of the elided hamza was transferred. Al-Mazini and al-Mubarrad criticized this reading, yet the Arabs say when beginning after a transfer, al-Humr (the reds); thus, this reading conforms to the usage of al-Humr, so there is no fault in it. Qalun, after the damma of the lam, brought a quiescent hamza in the place of the waw, as in the saying: "The most beloved of the kindlers to Musa." And just as some read ‘ala su’qihi (on its stalk); there is an irregularity in it. In the codex of Ubayy, ‘Aad is non-diptote (ghayr masruf) due to the factors of proper noun status and femininity. As for those who make it diptote, it is either with consideration of the "tribe" (hayy) or by treating it like the name Hind, because it is a trilateral noun with a quiescent middle.