SHAFAQNA – It is narrated from Imam Hussain (AS) who said: A group of people worship God for rewards, this is the worship of traders; another group worship the Supreme Being out of fear, this is the worship of slaves; and a third group worship for the sake of thanking Allah (SWT), this is the worship of free men and women and is the best of worships .
 Beharul Anwaar, Vol. 78, Page 117. & Moso’ah Kalamatul Imam Hussain (AS), Page 748, Hadith 906. & Balaghatal Imam Ali ibnal Hussain (AS), Page 171.