Hadith 195

Sahih Muslim

Book 13: The Book of Fasting

Chapter 26

It is Permissible to delay making up missed Ramadan Fasts until before the next Ramadan comes, and this is for those who broke the fast for a reason such as sickness, travel, menstruation and the like

باب قَضَاءِ رَمَضَانَ فِي شَعْبَانَ ‏

Sahih Muslim 1146c
وَحَدَّثَنِيهِ مُحَمَّدُ بْنُ رَافِعٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا ابْنُ جُرَيْجٍ، حَدَّثَنِي يَحْيَى، بْنُ سَعِيدٍ بِهَذَا الإِسْنَادِ وَقَالَ فَظَنَنْتُ أَنَّ ذَلِكَ لِمَكَانِهَا مِنَ النَّبِيِّ صلى الله عليه وسلم ‏.‏ يَحْيَى يَقُولُهُ ‏.‏
In another version of the previous hadith, the words are:

" Yahya said: I think it was due to the regard for the Messenger of Allah (ﷺ)."