Mujahid (may Allah have mercy on him) narrates: Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) recited this verse: "For those who are able to do it (with hardship), a ransom (as substitute) of feeding a poor person is required." Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) says: This refers to an old man who does not have the ability to fast. He will leave the fast and, in exchange for each day, feed a poor person, which will be half a sa’ of wheat.