Qatadah (may Allah have mercy on him) narrates that Anas (may Allah be pleased with him) became weak one year before his death, so he did not fast and ordered his family to feed a poor person in place of each day. Hisham said: He then fed thirty.
(In the hadith of Hisham it says that he then fed thirty poor people.)
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8320