من لا يحضره الفقيه, volume 2, page 152

Hadith.2005 - Musa ibn Bakr narrated from Al-Fudayl, from Abu Abdullah (as), regarding a man obligated to fast for a month who completed fifteen days of fasting and then was interrupted by some matter. Imam (as) said: "If he has fasted fifteen days, he may make up the remaining days. However, if he has fasted less than fifteen days, it will not suffice him, and he must start anew and fast a complete month."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.

Hadith.2006 - Mansur ibn Hazim narrated from Abu Abdullah (as) regarding a man who was fasting as expiation (for zihar) during Sha’ban and then Month of Ramadan began. Imam (as) said: "He should fast the Month of Ramadan and then resume the expiation fast. However, if he was fasting for expiation and completed half a day more than the midpoint (of the fast), he can simply complete the remaining days."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.

Hadith.2007 - Ibn Mahbub narrated from Abu Ayyub from Abu Abdullah (as) regarding a man who had to fast for two consecutive months as expiation for zihar. He fasted the month of Dhu al-Qa'dah, and then the month of Dhu al-Hijjah began. Imam (as) said: "He should fast the entirety of Dhu al-Hijjah, except for the Days of Tashreeq, and then make up for those three days at the beginning of Muharram to complete the two consecutive months of fasting. He should not approach his wife until he has completed fasting the three Days of Tashreeq that he missed. There is no issue if he fasts one month and then a few days of the following month, but if illness or another impediment arises, he may interrupt the fast and then complete the two consecutive months afterward."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.

Hadith.2008 - Aban ibn Uthman narrated from Abu Maryam Al-Ansari, who narrated from Abu Abdullah (as), who said: "If a man fasted part of the Month of Ramadan but then remained ill until he died, there is no obligation to make up the missed fasts. However, if he recovered and then fell ill again before passing away, and he had wealth, charity should be given on his behalf for each day missed in the amount of a mudd. If he did not have wealth, his guardian should fast on his behalf."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.