Tafsir of Hud 11:50

(And to ‘Ad) is linked to an omitted verb that is coordinated with His, the Exalted’s, saying: (We sent) in the story of Nuh, which is the regent [governor] for His saying, the Exalted: (their brother), meaning: "And We sent to ‘Ad their brother," meaning: one of them in lineage, as they say: "O brother of the Arabs." The prepositional phrase is placed first so that the pronoun may return to it.

It has been said: (And to ‘Ad, their brother) is coordinated with His, the Exalted’s, saying: (Nuh to his people), with the accusative object coordinated with the accusative object, and the prepositional phrase with the prepositional phrase. This is from the category of coordinating upon the two dependents of a single regent, and it is not among the matters that are disputed. Yes, the first is closer [more appropriate], as is in al-Bahr, due to the length of the separation caused by the many sentences between the coordinated singulars.

His, the Exalted’s, saying: (Hud) is an explanatory apposition (‘atf bayan) for "their brother," and it is permissible for it to be a substitute (badal) for it. He, peace be upon him, was the cousin of the father of ‘Ad, and he was sent to them as one of them so that it might be more conducive to their following him.

(He said) is an explanatory commencement (isti'naf bayani), as his mission, peace be upon him, gave rise to the question regarding what he said to them and what he called them to, as if it were said: "What did he say to them when he was sent to them?" So it was said: He said: (O my people). He called out to them with this to solicit their affection. Ibn Muhaysin read it: "Ya qawmu" with a damma, which is a dialect for the vocative phrase added to the ya [the first-person possessive], which Sibawayh and others narrated.

(Worship Allah), meaning: make Him One. They were polytheists who worshipped idols. What indicates that this is what is intended is His, the Exalted’s, saying: (You have no god other than Him); for it is a commencement that serves the function of explaining the worship that was commanded and providing the reason for the command to perform it, as if it were said: "Singularize Him in worship and do not associate anything with Him, for you have no god other than Him, the Exalted." This is because there is no account taken of worship alongside polytheism, so the command to perform it necessitates the command to singularize Him, the Exalted, in it.

(Other than Him) is in the nominative case (raf') as an adjective for "god," considering its position, because it is the subject of the prepositional phrase due to its reliance upon negation. Al-Kisa'i read it in the genitive case (jarr) as an adjective for it, following its literal form.

(You are)—that is, you are nothing—(except fabricators), by your attribution of divinity to other than Him, the Exalted—as al-Hasan said—or by your saying: "Allah, the Exalted, has commanded us to worship idols."

(Above that, may He be exalted with a great exaltation.)