عَنْ حَسَّانِ بْنِ نُوحٍ الْحِمْصِيِّ قَالَ: رَأَيْتُ عَبْدَ اللَّهِ بْنَ بُسْرٍ رَضِيَ اللَّهُ عَنْهُ يَقُولُ: تَرَوْنَ كَفِّي هَذِهِ؟ فَأَشْهَدُ أَنِّي وَضَعْتُهَا عَلَى كَفِّ مُحَمَّدٍ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ (وَفِي رِوَايَةٍ: بَايَعْتُ بِهَا رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ وَنَهَى عَنْ صِيَامِ يَوْمِ السَّبْتِ إِلَّا فِي فَرِيضَةٍ، وَقَالَ: ((إِنْ لَمْ يَجِدْ أَحَدُكُمْ إِلَّا لِحَاءَ شَجَرَةٍ فَلْيُفْطِرْ عَلَيْهِ))
Hassan bin Noah Hamsi says: I saw Sayyiduna Abdullah bin Busr, he said: O people! Do you see this palm of mine? I testify that I placed it on the palm of our Prophet Muhammad (peace and blessings be upon him) and pledged allegiance to him. The fact is that the Messenger of Allah (peace and blessings be upon him) forbade fasting only on Saturday, except for an obligatory fast. Also, the Prophet (peace and blessings be upon him) said: If you find nothing to eat except the bark of a tree, then eat that (to indicate that you are not fasting).