قُلِ ادْعُوا اللَّـهَ أَوِ ادْعُوا الرَّحْمَـٰنَ ۖ أَيًّا مَّا تَدْعُوا فَلَهُ الْأَسْمَاءُ الْحُسْنَىٰ ۚ وَلَا تَجْهَرْ بِصَلَاتِكَ وَلَا تُخَافِتْ بِهَا وَابْتَغِ بَيْنَ ذَٰلِكَ سَبِيلًا ﴿١١٠﴾ وَقُلِ الْحَمْدُ لِلَّـهِ الَّذِي لَمْ يَتَّخِذْ وَلَدًا وَلَمْ يَكُن لَّهُ شَرِيكٌ فِي الْمُلْكِ وَلَمْ يَكُن لَّهُ وَلِيٌّ مِّنَ الذُّلِّ ۖ وَكَبِّرْهُ تَكْبِيرًا ﴿١١١﴾

Qulid'ullaaha awid'ur-Rahmaana ayyam-maa tad'oo falahul-Asmaaa'ul-Husnaa; wa laa tajhar bi-Salaatika wa laa tukhaafit bihaa wabtaghi baina zaalika sabeelaa. Wa qulil-Hamdu lillaahil-lazee lam yattakhiz waladan wa lam yakul-lahoo shareekun fil-mulki wa lam yakul-lahoo waliyyum-minaz-zulli wa kabbirhu takbeeraa.

(110) Say, "Call upon Allah or call upon the Most Merciful. Whichever [name] you call - to Him belong the best names." And do not recite [too] loudly in your prayer or [too] quietly but seek between that an [intermediate] way. (111) And say, "Praise to Allah, who has not taken a son and has had no partner in [His] dominion and has no [need of a] protector out of weakness; and glorify Him with [great] glorification."

Reference: Surah Isra 17: 110-111