Tafsir of Saba' 34:45

Then, He, the Exalted, threatened them by His saying, Glorified is He: "And those before them denied"—from the preceding nations and the bygone generations—"and they have not attained"—meaning the people of Makkah—"a tenth of what We had given them." It is said: The mi‘shār is the tenth of the tenth, though Ibn ‘Aṭiyyah did not approve of this. Al-Māwardī said: The intended meaning is an exaggeration of diminishment; that is, they did not reach even the slightest fraction of what We gave those deniers in terms of longevity, physical strength, and abundance of wealth. "So they denied My messengers"—meaning those deniers—"then how was My rejection?"—meaning My disapproval of them through destruction. Thus, let these [people] beware of the like of that.

The first fāʾ (in fa-kadhaba) is causative, and the first "denied" (kadhaba) is treated as an intransitive verb; that is, those before them performed the act of denial and proceeded with it. Similar to this is when a person says, "So-and-so proceeded to disbelief, so he disbelieved in Muhammad (peace be upon him)." From this, they stated: "They denied My messengers" is a conjunction added to "those before them denied," where the specific is joined to the general, and it acts as an explanation of the meaning. "And they have not attained" is a parenthetical clause. The second fāʾ is faṣīḥah (eloquent/implied), so the meaning is: "When they denied My messengers, My rejection through destruction came upon them; so how was My rejection of them?" He made the destruction a "rejection" (denial/disapproval), treating the action as a statement, as in the saying:

We curse with actions, not with speech.

Or as in:

A greeting among them is a painful blow.

Some permitted that the taf‘īl form in "denied" (kadhaba) signifies frequency, and in "they denied" (kadhabū) it signifies transitivity, while the subject in both is the same; meaning, they multiplied their denial and became accustomed to it until it became their nature, to the point that they grew bold enough to deny the messengers. On both interpretations, there is no repetition.

It has also been permitted that "they denied My messengers" is conjoined to "and they have not attained," making it part of the parenthetical clause, with the pronoun referring to the people of Makkah. This means: these people have not attained a tenth of what We gave those first deniers, and they surpassed them in denial because their denial of the Seal of the Prophets (upon him and them be blessings and peace) is a denial of all the messengers (peace be upon them) from two perspectives. Upon this view, there is no suspicion of repetition, as is not hidden.

The fact that the sentence "and they have not attained" is parenthetical is the most apparent view. To claim that "those before them denied" is a preamble so that this sentence would not be parenthetical is refuted by "then how was My rejection," because its meaning is exclusively for the first deniers; thus, there is no cohesion without stating that it is parenthetical.

Returning the pronoun in "they attained" to the people of Makkah, and the object pronoun in "what We gave them" to "those before them," and explaining the relative pronoun (al-ladhīna) as you have heard, is what is narrated from Ibn ‘Abbās, Qatādah, and Ibn Zayd. It is also said that the first pronoun refers to those before them and the second to the people of Makkah—that is: those before them did not attain a tenth of what We gave these people in terms of clear signs and guidance. Another view is that both pronouns refer to those before them; that is, they denied, and in their gratitude for the blessing and in their reciprocal response, they did not attain a tenth of the blessings and kindness We gave them. Abū Ḥayyān deemed this the most likely, justifying it by the consistency of the pronouns, as he assigned the pronoun in "so they denied" to those before them. So, do not be heedless.