Musnad Ahmad 30:2138

'Affan narrated to us, Wuhayb narrated to us, al-Nu'man ibn Rashid narrated to us, from al-Zuhri, from Sa'id ibn al-Musayyib, from Abu Hurayrah, who said: "The worst of food is the food of the wedding feast (walimah), to which the rich are invited and the poor are turned away. And whoever refuses the invitation has disobeyed Allah and His Messenger."