Muhammad ibn Yaqub, from Muhammad ibn Yahya, from Muhammad ibn al-Husayn, from Safwan ibn Yahya, from al-Ala, from Muhammad ibn Muslim, from Abu Abdillah عليه السلام, peace be upon him, who said: Imam عليه السلام said: “When a man travels in the month of Ramadan and leaves after half of the day, then he must fast that day and count it as part of the month of Ramadan. Then, when he enters a town before the rising of dawn while intending to stay in it, then he must fast that day. But if he enters after the rising of dawn, then there is no fast upon him, though if he wishes, he may fast.”