Surah Al-Inshiqaq 84:20

فَمَا لَهُمْ لَا يُؤْمِنُونَ

So what is [the matter] with them [that] they do not believe,

Translation: Saheeh International

Tafsir

So what is wrong with them that is the disbelievers that they do not have faith that is to say what is there to prevent them from embracing faith; or what argument do they have for neglecting it despite the existence of proofs for it

Excerpt from Tafsir al-Jalalayn, commentary on 84:20, via Quran.com. The reader has the full commentary and 9 more tafsirs.