Sahih Muslim 1113a
Ibn Abbas (Allah be pleased with him) reported that the Messenger of Allah ﷺ went out during the month of Ramadan in the year of Victory (when Mecca was conquered) and was fasting till he reached Kadid (a canal situated at a distance of forty-two miles from Mecca) and he then broke the fast. And it was the habit of the Companions of the Messenger of Allah ﷺ to follow him in every new thing (or act). So they followed him also (in this matter).
حَدَّثَنِي يَحْيَى بْنُ يَحْيَى، وَمُحَمَّدُ بْنُ رُمْحٍ، قَالاَ أَخْبَرَنَا اللَّيْثُ، ح وَحَدَّثَنَا قُتَيْبَةُ بْنُ، سَعِيدٍ حَدَّثَنَا لَيْثٌ، عَنِ ابْنِ شِهَابٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ، عَنِ ابْنِ عَبَّاسٍ، - رضى الله عنهما - أَنَّهُ أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ ﷺ خَرَجَ عَامَ الْفَتْحِ فِي رَمَضَانَ فَصَامَ حَتَّى بَلَغَ الْكَدِيدَ ثُمَّ أَفْطَرَ وَكَانَ صَحَابَةُ رَسُولِ اللَّهِ ﷺ يَتَّبِعُونَ الأَحْدَثَ فَالأَحْدَثَ مِنْ أَمْرِهِ .