Tafsir of Ar-Rum 30:47

(And We have certainly sent before you messengers to their people): This is a parenthetical clause to comfort the Prophet, may Allah bless him and grant him peace, by mentioning those who came before him. It is framed in a way that includes a promise for him—peace be upon him—and a threat to those who disobeyed him. In this, there is also a warning against failing to fulfill the requirements of gratitude.

The intent by "their people" is "their nations." The singular form is used for brevity, as there is no ambiguity. The meaning is: "We have certainly sent messengers before you to their nations, just as We have sent you to your people."

(So they came to them with clear proofs): Meaning, each messenger came to his people with the clear proofs specific to them, just as you have come to your people with your clear proofs.

(And We took retribution from those who committed crimes): The fa (so) here is fasihah (eloquent/explanatory), meaning: "Some believed and some disbelieved, so We took retribution." It is also said it means: "They disbelieved them, so We took retribution from them." The use of the relative pronoun ("those who") in place of a pronoun referring back to them is to signify the cause and to draw attention to the nature of the omitted matter. It is also permissible that this is a detailed explanation of a generality, meaning that among them were the criminal who was subdued and the believer who was granted victory.

(And it was incumbent upon Us to aid the believers): This contains additional honor and distinction for the believers, as they are rendered deserving—by Allah’s decree—of His aid. It also signals that the retribution was for their sake. By "believers" is meant those who encompass the messengers, peace be upon them. It is also permissible to restrict this specifically to the messengers by treating the definite article as referring back to a specific group. The apparent meaning of the verse is that this aid occurs in this worldly life, though some traditions suggest it is not exclusive to it and that it is general for all believers, thereby including those of the nation who came after the messengers.

Ibn Abi Hatim, At-Tabarani, and Ibn Marduyah recorded from Abu al-Darda that he said: I heard the Messenger of Allah, may Allah bless him and grant him peace, say: "There is no Muslim person who defends the honor of his brother except that it becomes incumbent upon Allah the Exalted to ward off the Fire of Hell from him on the Day of Resurrection." Then, peace and blessings be upon him, he recited: "And it was incumbent upon Us to aid the believers."

This indicates that "incumbent" (haqqan) is the predicate of kana (it was), and "to aid the believers" (nasru al-mu'minin) is its subject, as is apparent. The subject was delayed because that which is attached to it acts as a separator, and to emphasize the predicate, as it is the point of interest, according to what is stated in al-Bahr.

Ibn Atiyyah said: Some reciters pause at "incumbent" (haqqan), treating the subject of kana as a pronoun referring to the retribution—meaning: "And the retribution was a right and justice, not injustice." Its return to that is similar to [the verse]: "Be just; that is nearer to righteousness" (5:8). And "to aid the believers" ('alayna nasru al-mu'minin) is an independent, commencing sentence. This, however, is contrary to the apparent meaning supported by the report, even if there is no inherent fault in its meaning.