The Book of Fasting
13/26. Chapter:
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
Sahih Muslim
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا عَبْدُ الْوَهَّابِ، ح وَحَدَّثَنَا عَمْرٌو النَّاقِدُ، حَدَّثَنَا سُفْيَانُ، كِلاَهُمَا عَنْ يَحْيَى، بِهَذَا الإِسْنَادِ وَلَمْ يَذْكُرَا فِي الْحَدِيثِ الشُّغْلُ بِرَسُولِ اللَّهِ صلى الله عليه وسلم .
This hadith is reported on the authority of Yahya with the same chain of transmitters but no mention is made of the duty to the Messenger of Allah (ﷺ).
Reference : Sahih Muslim 1146dIn-book reference : Book 13, Hadith 196USC-MSA web (English) reference : Book 6, Hadith 2551