عَنْ مَحْمُودِ بْنِ لَبِيدٍ رضي الله عنه أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «إِنَّ أَخْوَفَ مَا أَخَافُ عَلَيْكُمُ الشِّرْكُ الْأَصْغَرُ» قَالُوا: وَمَا الشِّرْكُ الْأَصْغَرُ يَا رَسُولَ اللهِ؟ قَالَ: «الرِّيَاءُ، يَقُولُ اللهُ عز وجل لَهُمْ يَوْمَ الْقِيَامَةِ إِذَا جُزِيَ النَّاسُ بِأَعْمَالِهِمْ: اذْهَبُوا إِلَى الَّذِينَ كُنْتُمْ تُرَاؤُونَ فِي الدُّنْيَا، فَانْظُرُوا هَلْ تَجِدُونَ عِنْدَهُمْ جَزَاءً؟».
The Prophet (may Allah's peace and blessings be upon him) informs that what he fears most for his Ummah is minor Shirk, which is showing off, i.e., doing good deeds for the sake of people. Then, he (may Allah's peace and blessings be upon him) informs of the punishment of those who show off with their good deeds as it will be said to them on the Day of Judgment: Go to those for the sake of whom you offered your good deeds and see if they have the ability to reward you for such deeds.
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