6. Abu Ali al-Ash’ariy has narrated from Muhammad ibn ‘Abd al-Jabbar from Safwan ibn Yahya from Yazid ibn Khalifah who has said the following: “I once complained before abu ‘Abd Allah عليه السلام, saying, ‘I get a headache if I fast the three days (recommended for every month) and it is difficult for me. He (the Imam) said, ‘You must do as I do when I travel. When traveling I pay charity for every day of one mud (a certain measurement) of the kind of food which is used in my family.’”