Surah Al-An'am, Verse 109

وَأَقۡسَمُواْ بِٱللَّهِ جَهۡدَ أَيۡمَٰنِهِمۡ لَئِن جَآءَتۡهُمۡ ءَايَةٞ لَّيُؤۡمِنُنَّ بِهَاۚ قُلۡ إِنَّمَا ٱلۡأٓيَٰتُ عِندَ ٱللَّهِۖ وَمَا يُشۡعِرُكُمۡ أَنَّهَآ إِذَا جَآءَتۡ لَا يُؤۡمِنُونَ١٠٩

wa-aqsamū bil-lahi jahda aymānihim la-in jāathum āyatun layu'minunna bihā qul innamā l-āyātu ʿinda l-lahi wamā yush'ʿirukum annahā idhā jāat lā yu'minūna

And they swear by Allāh their strongest oaths that if a sign came to them, they would surely believe in it. Say, "The signs are only with [i.e., from] Allāh." And what will make you perceive that even if it [i.e., a sign] came, they would not believe.