Quran 17, Al-Isra' (The Night Journey) ⓘ

17:110Say (unto mankind): Cry unto Allah, or cry unto the Beneficent, unto whichsoever ye cry (it is the same). His are the most beautiful names. And thou (Muhammad), be not loud-voiced in thy worship nor yet silent therein, but follow a way between.

قُلِ ادْعُوا اللَّهَ أَوِ ادْعُوا الرَّحْمَنَ أَيًّا مَا تَدْعُوا فَلَهُ الْأَسْمَاءُ الْحُسْنَى وَلَا تَجْهَرْ بِصَلَاتِكَ وَلَا تُخَافِتْ بِهَا وَابْتَغِ بَيْنَ ذَلِكَ سَبِيلًا