That he heard Ibn ʿAbbas reciting the Divine Verse:-- "And for those who can fast they had a choice either fast, or feed a poor for every day.." (2.184) Ibn ʿAbbas said, "This Verse is not abrogated, but it is meant for old men and old women who have no strength to fast, so they should feed one poor person for each day of fasting (instead of fasting).
أَنْ يَصُومَا فَلْيُطْعِمَانِ مَكَانَ كُلِّ يَوْمٍ مِسْكِينًا