What does 'Kallā sayaʿlamūn' mean in Surah An-Naba 78:4-5?
Answer
In Surah An-Naba 78:4-5, 'Kallā sayaʿlamūn' (كَلَّا سَيَعْلَمُونَ) means 'No indeed; they will come to know,' followed in verse 5 by 'Thumma kallā sayaʿlamūn' — 'Again, no indeed; they will come to know.' The word 'Kallā' is a sharp Arabic particle of rebuke and deterrence, here rebutting those who disputed and doubted the resurrection mentioned in the opening verses (78:1-3, 'the great announcement about which they differ'). The phrase 'sayaʿlamūn' ('they will come to know') is a veiled but severe threat: those who reject the Day of Judgment will inevitably learn the truth of it when its terrors and consequences befall them. Classical exegetes including al-Saʿdī, al-Ṭabarī, Ibn Kathīr, and al-Qurṭubī explain that the second verse repeats the warning with 'Thumma' ('then/again') for emphasis and intensification — doubling the certainty of the coming reckoning so the deniers cannot dismiss it. The structure leaves the object of their future knowledge deliberately unstated, which heightens the dread: they will come to know something so grave it needs no naming.
Qur’anic evidence — read the full study of 78:4 →
In more depth
Some exegetes, noted by al-Ṭabarī and al-Qurṭubī, held that the first 'they will come to know' threatens the disbelievers while the second relates to the believers' reward. The view conveyed as stronger, however, reads both as escalating warnings to the deniers, with the repetition serving emphasis.