Yahya related to me from Malik from Ibn Shihab from Ubaydullah ibn Abdullah ibn Utba ibn Masud from Abdullah ibn Abbas that the Messenger of Allah ﷺ left for Makka in Ramadan during the year of the conquest, and fasted until he reached al-Kadid. He then broke the fast, and so everyone else did so as well. What people used to do was act according to whatever the Messenger of Allah ﷺ had done most recently.

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ بْنِ مَسْعُودٍ، عَنْ عَبْدِ اللَّهِ بْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ ﷺ خَرَجَ إِلَى مَكَّةَ عَامَ الْفَتْحِ فِي رَمَضَانَ فَصَامَ حَتَّى بَلَغَ الْكَدِيدَ ثُمَّ أَفْطَرَ فَأَفْطَرَ النَّاسُ وَكَانُوا يَأْخُذُونَ بِالأَحْدَثِ فَالأَحْدَثِ مِنْ أَمْرِ رَسُولِ اللَّهِ ﷺ .