Hadith 1816
۞
237. Amīr al-mu’minīn, peace be upon him, said: A group of people worshipped Allāh out of desire for reward surely, this is the worship of traders. Another group worshipped Allāh out of fear, this is the worship of slaves. Still another group worshipped Allāh out of gratefulness, this is the worship of free men.
٢٣٧. وَقَالَ (عليه السلام): إِنَّ قَوْماً عَبَدُوا اللهَ رَغْبَةً فَتِلْكَ عِبَادَةُ التُّجَّارِ، وَإِنَّ قَوْماً عَبَدُوا اللهَ رَهْبَةً فَتِلْكَ عِبَادَةُ الْعَبِيدِ، وَإِنَّ قَوْماً عَبَدُوا اللهَ شُكْراً فَتِلْكَ عِبَادَةُ الْأَحْرَارِ.