say call him allah or call him arrahman whatever the name you call him by all his names are beautiful. do not say your prayers too loudly or in too low a voice but follow a middle coarse.
قل ادعوا الله أو ادعوا الرحمن أيا ما تدعوا فله الأسماء الحسنى ولا تجهر بصلاتك ولا تخافت بها وابتغ بين ذلك سبيلا