Surah Al-A'raf (The Heights), Verse 203

وَاِذَا لَمْ تَاْتِهِمْ بِاٰیَةٍ قَالُوْا لَوْلَا اجْتَبَیْتَهَا قُلْ اِنَّمَاۤ اَتَّبِعُ مَا یُوْحٰۤی اِلَیَّ مِنْ رَّبِّیْ هٰذَا بَصَآىِٕرُ مِنْ رَّبِّكُمْ وَهُدًی وَّرَحْمَةٌ لِّقَوْمٍ یُّؤْمِنُوْنَ ۟

Wa izaa lam ta'tihim bi aayatin qaaloo law lajtabai tahaa; qul innamaaa attabi'u maa yoohaaa ilaiya mir Rabbee; haazaa basaaa'iru mir Rabbikum wa hudanw wa rahmatul liqawminy yu'minoon

“If thou bring them not a revelation, they say: "Why hast thou not got it together?" Say: "I but follow what is revealed to me from my Lord: this is (nothing but) lights from your Lord, and Guidance, and mercy, for any who have faith."”

Quran 7:203 (Yusuf Ali Translation)