Sayyiduna Abu Hurayrah (may Allah be pleased with him) says: The Prophet (peace and blessings be upon him) ate in the house of Sayyiduna Abbas (may Allah be pleased with him), or perhaps in the house of Sayyiduna Hamzah (may Allah be pleased with him), and said: "Some people of my Ummah will plunge into (wrongfully taking) what Allah Almighty has granted to His Messenger as fay' (spoils gained without fighting), and they will have no share other than it. And the expiation of sins (lies in these deeds): performing ablution thoroughly, going to the mosque with many steps, and waiting for one prayer after another."
Imam al-Bazzar recorded it, and its chain is sahih (authentic).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2130