Sahih Muslim Book - 13, Hadith - 2618

حَدَّثَنِى عَمْرٌو النَّاقِدُ حَدَّثَنَا إِسْمَاعِيلُ بْنُ إِبْرَاهِيمَ عَنِ الْجُرَيْرِىِّ عَنْ أَبِى نَضْرَةَ عَنْ أَبِى سَعِيدٍ الْخُدْرِىِّ - رضى الله عنه - قَالَ كُنَّا نَغْزُو مَعَ رَسُولِ اللَّهِ -صلى الله عليه وسلم- فِى رَمَضَانَ فَمِنَّا الصَّائِمُ وَمِنَّا الْمُفْطِرُ فَلاَ يَجِدُ الصَّائِمُ عَلَى الْمُفْطِرِ وَلاَ الْمُفْطِرُ عَلَى الصَّائِمِ يَرَوْنَ أَنَّ مَنْ وَجَدَ قُوَّةً فَصَامَ فَإِنَّ ذَلِكَ حَسَنٌ وَيَرَوْنَ أَنَّ مَنْ وَجَدَ ضَعْفًا فَأَفْطَرَ فَإِنَّ ذَلِكَ حَسَنٌ.

It was narrated that Abu Saeed Al-Khudri [may Allah be pleased with them] said: “We went out on a campaign with the Messenger of Allah (SAW) during the month of Ramadan, and some of us were fasting and some were not. Those who were fasting did not find fault with those who were not, and those who were not fasting did not find fault with those who were. They thought that for those who found the strength and fasted, that was good; and they thought that for those who found themselves weak and did not fast, that was good too.”