Quran 9:124 — Ultimatum (Bara'ah)

When a sura was revealed, some of them would say, "Did this sura strengthen the faith of anyone among you?" Indeed, it did strengthen the faith of those who believed, and they rejoice in any revelation.

[9:123] O you who believe, you shall fight the disbelievers who attack you—let them find you stern—and know that GOD is with the righteous.

[9:125] As for those who harbored doubts in their hearts, it actually added unholiness to their unholiness, and they died as disbelievers.