Surah Al-A'raf, Verse 203

وَإِذَا لَمۡ تَأۡتِهِم بِـَٔايَةٖ قَالُواْ لَوۡلَا ٱجۡتَبَيۡتَهَاۚ قُلۡ إِنَّمَآ أَتَّبِعُ مَا يُوحَىٰٓ إِلَيَّ مِن رَّبِّيۚ هَٰذَا بَصَآئِرُ مِن رَّبِّكُمۡ وَهُدٗى وَرَحۡمَةٞ لِّقَوۡمٖ يُؤۡمِنُونَ٢٠٣

wa-idhā lam tatihim biāyatin qālū lawlā ij'tabaytahā qul innamā attabiʿu mā yūḥā ilayya min rabbī hādhā baṣāiru min rabbikum wahudan waraḥmatun liqawmin yu'minūna

And when you, [O Muḥammad], do not bring them a sign [i.e., miracle], they say, "Why have you not contrived it?" Say, "I only follow what is revealed to me from my Lord. This [Qur’ān] is enlightenment from your Lord and guidance and mercy for a people who believe."