Sunan Abi Dawud, Hadith 2399

Narrated Anas : We travelled along with the Prophet during Ramadan. Some of us were fasting and other broke their fast. Those who fasted did not find fault with those who broke, and those who broke their fast did not find fault with those who fasted.

حَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، حَدَّثَنَا زَائِدَةُ، عَنْ حُمَيْدٍ الطَّوِيلِ، عَنْ أَنَسٍ، قَالَ سَافَرْنَا مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم فِي رَمَضَانَ فَصَامَ بَعْضُنَا وَأَفْطَرَ بَعْضُنَا فَلَمْ يَعِبِ الصَّائِمُ عَلَى الْمُفْطِرِ وَلاَ الْمُفْطِرُ عَلَى الصَّائِمِ ‏.‏

sunnah.com

also referenced under: Hadith 2405 (DarusSalam)