Tafsir of As-Saff 61:8

"They intend to extinguish the light of Allah with their mouths..."

This is a representation of their efforts to invalidate the truth, likened to the state of one who blows at the sun with his mouth to extinguish it—a mockery and ridicule of them, similar to what people say: "He is blowing out the eye of the sun." Some prominent scholars held that the intended meaning of the "light" is His, the Almighty’s, true religion, as was narrated from As-Suddi by way of isti'arah tasrihiyyah (explicit metaphor). The same applies to His, the Exalted’s, saying: "...and Allah will perfect His light," where "perfecter" (mutimm) serves as a tajrid (abstraction). In His saying, "...with their mouths," there is tawriyah (double entendre).

Ibn Abbas and Ibn Zayd said: They intend to invalidate the Quran and deny it with their speech. Ibn Bahr said: They intend to invalidate the proofs of Allah—Exalted is He—by their denial. Ad-Dahhak said: They intend the destruction of the Messenger—may Allah exalt his mention and grant him peace—through rumors. It was also said: They intend to invalidate the status of the Prophet—may Allah exalt his mention and grant him peace—and conceal his emergence through their words and lies. It has been narrated from Ibn Abbas that the revelation was delayed for forty days, so Ka'b ibn al-Ashraf said: "O company of Jews, rejoice! Allah has extinguished the light of Muhammad regarding what was being revealed to him, and he will never perfect his light." The Messenger—may Allah exalt his mention and grant him peace—became sorrowful, and then “They intend…” up to the end of the verse was revealed.

Regarding (yuriduna liyutfi'u) [they intend to extinguish], there are several schools of thought:

1. The lam (the 'li' in liyutfi'u) is redundant, and the verb is in the subjunctive mood due to a hidden an following it. It was added to emphasize the meaning of intent, because the lam of purpose implies will and aim, just as the lam was added in "I do not care for [la ubali lak]" to emphasize the meaning of possession.
2. It is a redundant lam for the sake of cause, and the object of yuriduna is omitted; meaning, they intend fabrication in order to extinguish.
3. The verb, meaning yuriduna, acts as a verbal noun (masdar) acting as the subject, and the lam is for purpose, with the prepositional phrase serving as the predicate; meaning, their intent is [directed] toward extinguishing. The discourse is analogous to "To hear of al-Ma'idi is better than to see him" from one perspective.
4. The lam is an infinitive marker (masdariyyah) meaning an (that) without requiring estimation, and the verbal noun serves as the object. This is frequent after verbs of intent and command.
5. Yuriduna is treated as an intransitive verb, interpreted as "they bring about the intent." It is said that this contains hyperbole, as if every intent of theirs is for the purpose of extinguishing. There is further discussion on this in the explanation of Al-Mughni and elsewhere.

Al-Arabiya, Nafi', Abu Bakr, Al-Hasan, Talha, Al-A'raj, and Ibn Muhaisin recited mutimm (perfecter) with tanwin, and nurahu (His light) in the accusative case as the object of mutimm.

"...even if the disbelievers dislike it."

This is a state (hal) of the hidden pronoun within mutimm, indicating that He—the Almighty—will perfect it to spite them.