Ata said: I heard Abu Hurayrah (may Allah be pleased with him) in this mosque saying: There are three things in which there is one mudd each: 1. the expiation for an oath, 2. the expiation for zihar, 3. the fidyah of feeding a poor person.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 19975