Sahih
Muslim
صحيح مسلم
13
The Book of Fasting
كتاب الصيام
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 1146 c
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)."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 .
Grade: Sahih