Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) said: "When you are invited to (eat) a trotter, accept."
(b) Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him): "A Muslim should accept his brother's invitation."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14528