Quran 6:109 Al-An'am, ayah 109 of 165

وَأَقْسَمُوا۟ بِٱللَّهِ جَهْدَ أَيْمَـٰنِهِمْ لَئِن جَآءَتْهُمْ ءَايَةٌ لَّيُؤْمِنُنَّ بِهَا ۚ قُلْ إِنَّمَا ٱلْـَٔايَـٰتُ عِندَ ٱللَّهِ ۖ وَمَا يُشْعِرُكُمْ أَنَّهَآ إِذَا جَآءَتْ لَا يُؤْمِنُونَ ۝١٠٩

6:109 And they swear a solemn oath by Allah that if there come unto them a portent they will believe therein. Say; Portents are with Allah and (so is) that which telleth you that if such came unto them they would not believe.