Say, "Call on God or call on the Gracious. Whichever it is you call on, to Him are the best names." Do not be loud/public in your contact prayer, nor quiet/private; but seek a path in between.
Translation endnotes
[17:110] The word ism comes from the root SMY and means "attribute, quality." Regardless of the language, all beautiful attributes may be used for God (the god). Divine attributes do not necessarily define or describe God in an objective sense, but define and describe our relationship with our Creator and the mutual expectations. The word allah (the god) is a contraction of al (the) and elah (god). The Quran uses the word elah (god) in many verses for allah (the god) in the proper context. For instance, in the last chapter of the Quran, God is referred to as "lord of the people." The famous Quranic declaration la ilaha illa allah, therefore, can be translated into English as "there is no god but the god". See 7:180, 26:198; 41:44. The Quran is correcting the tone of the recitation and manner of the sala prayer performed by Meccan polytheists. Despite this verse reminding us of a moderate tone of voice and moderate display of prayer, the followers of hadith and sunna, like their ancestors, either pray loudly (night time) or quietly (day time). Some even use prayer as political demonstration. This verse simply reminds us not to be ashamed of our prostration before God, nor use it as a means of showing off.