Al-Isra 17:110

Quli odAAoo Allaha awi odAAoo arrahmanaayyan ma tadAAoo falahu al-asmao alhusnawala tajhar bisalatika wala tukhafitbiha wabtaghi bayna thalika sabeela

Say, "Call upon Allāh or call upon the Most Merciful [ar-Raḥmān]. 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.

Say, “Call (Him by the name of) Allah or Ar-RaHmān, in whichever way you call, His are the Best Names.” Do not be (too) loud in your Salāh, nor be (too) low in it, and seek a way in between.