Muhammad ibn Yaqub from Ali ibn Ibrahim from his father from Ibn Abi Umayr from Karam, who said: I (narrator) said to Abu Abdillah عليه السلام, peace be upon him: “I have made it binding upon myself that I fast until the Qa’im (ajf), may Allah سبحانه وتعالى hasten his relief, rises.” Imam عليه السلام said: “Fast, but do not fast while travelling, nor on the two Eids, nor on the days of tashriq (ayyam al-tashriq), nor on the day concerning which there is doubt whether it is from the month of Ramadan.”