When the Verse:-- 'Those who believe and mix not their belief with wrong." was revealed, the companions of the Prophet ﷺ said, "Who amongst us has not mixed his belief with wrong?" Then Allah revealed: "Join none in worship with Allah, Verily joining others in worship with Allah is a great wrong indeed."  

لَمَّا نَزَلَتِ {الَّذِينَ آمَنُوا وَلَمْ يَلْبِسُوا إِيمَانَهُمْ بِظُلْمٍ} قَالَ أَصْحَابُ النَّبِيِّ ﷺ أَيُّنَا لَمْ يَلْبِسْ إِيمَانَهُ بِظُلْمٍ فَنَزَلَتْ {لاَ تُشْرِكْ بِاللَّهِ إِنَّ الشِّرْكَ لَظُلْمٌ عَظِيمٌ }  

When the Verse:-- 'Those who believe and mix not their belief with wrong.' was revealed, the Muslims felt it very hard on them and said, "O Messenger of Allah ﷺ! Who amongst us does not do wrong to himself?" He replied, "The Verse does not mean this. But that (wrong) means to associate others in worship to Allah: Don't you listen to what Luqman said to his son when he was advising him," O my son! Join not others in worship with Allah. Verily joining others in worship with Allah is a great wrong indeed." (31.13)  

لَمَّا نَزَلَتِ {الَّذِينَ آمَنُوا وَلَمْ يَلْبِسُوا إِيمَانَهُمْ بِظُلْمٍ} شَقَّ ذَلِكَ عَلَى الْمُسْلِمِينَ فَقَالُوا يَا رَسُولَ اللَّهِ أَيُّنَا لاَ يَظْلِمُ نَفْسَهُ قَالَ لَيْسَ ذَلِكَ إِنَّمَا هُوَ الشِّرْكُ أَلَمْ تَسْمَعُوا مَا قَالَ لُقْمَانُ لاِبْنِهِ وَهْوَ يَعِظُهُ {يَا بُنَىَّ لاَ تُشْرِكْ بِاللَّهِ إِنَّ الشِّرْكَ لَظُلْمٌ عَظِيمٌ }