Sunan Abi Dawud, Hadith 3733

Abu Hurairah said: The worst kind of food is that at a wedding feast to which the rich are invited and from which the poor are left out. If anyone does not attend the feast to which he was invited, he has disobeyed Allah and His Apostle (may peace upon him).

حَدَّثَنَا الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّهُ كَانَ يَقُولُ شَرُّ الطَّعَامِ طَعَامُ الْوَلِيمَةِ يُدْعَى لَهَا الأَغْنِيَاءُ وَيُتْرَكُ الْمَسَاكِينُ وَمَنْ لَمْ يَأْتِ الدَّعْوَةَ فَقَدْ عَصَى اللَّهَ وَرَسُولَهُ ‏.‏

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also referenced under: Hadith 3742 (DarusSalam)