Sahih al-Bukhari, Volume 8, Book 78, Hadith 644 (USC-MSA) ⓘ

Narrated Zahdam: There was a relation of love and brotherhood between this tribe of Jarm and Al-Ash`ariyin. Once we were with Abu Musa Al-Ash`ari, and then a meal containing chicken was brought to Abu Musa, and there was present, a man from the tribe of Taimillah who was of red complexion as if he were from non-Arab freed slaves. Abu Musa invited him to the meal. He said, "I have seen chickens eating dirty things, so I deemed it filthy and took an oath that I would never eat chicken." On that, Abu Musa said, "Get up, I will narrate to you about that. Once a group of the Ash`ariyin and I went to Allah's Messenger and asked him to provide us with mounts; he said, 'By Allah, I will never give you any mounts nor do I have anything to mount you on.' Then a few camels of war booty were brought to Allah's Messenger, and he asked about us, saying, 'Where are the Ash-'ariyin?' He then ordered five nice camels to be given to us, and when we had departed, we said, 'What have we done? Allah's Messenger had taken the oath not to give us any mounts, and that he had nothing to mount us on, and later he gave us that we might ride? Did we take advantage of the fact that Allah's Messenger had forgotten his oath? By Allah, we will never succeed.' So we went back to him and said to him, 'We came to you to give us mounts, and you took an oath that you would not give us any mounts and that you had nothing to mount us on.' On that he said, 'I did not provide you with mounts, but Allah did. By Allah, if I take an oath to do something, and then find something else better than it, I do that which is better and make expiation for the dissolution of the oath.' "

حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا عَبْدُ الْوَهَّابِ، عَنْ أَيُّوبَ، عَنْ أَبِي قِلاَبَةَ، وَالْقَاسِمِ التَّمِيمِيِّ، عَنْ زَهْدَمٍ، قَالَ كَانَ بَيْنَ هَذَا الْحَىِّ مِنْ جَرْمٍ وَبَيْنَ الأَشْعَرِيِّينَ وُدٌّ وَإِخَاءٌ، فَكُنَّا عِنْدَ أَبِي مُوسَى الأَشْعَرِيِّ، فَقُرِّبَ إِلَيْهِ طَعَامٌ فِيهِ لَحْمُ دَجَاجٍ وَعِنْدَهُ رَجُلٌ مِنْ بَنِي تَيْمِ اللَّهِ أَحْمَرُ كَأَنَّهُ مِنَ الْمَوَالِي، فَدَعَاهُ إِلَى الطَّعَامِ فَقَالَ إِنِّي رَأَيْتُهُ يَأْكُلُ شَيْئًا فَقَذِرْتُهُ، فَحَلَفْتُ أَنْ لاَ آكُلَهُ‏.‏ فَقَالَ قُمْ فَلأُحَدِّثَنَّكَ عَنْ ذَاكَ، إِنِّي أَتَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم فِي نَفَرٍ مِنَ الأَشْعَرِيِّينَ نَسْتَحْمِلُهُ فَقَالَ ‏"‏ وَاللَّهِ لاَ أَحْمِلُكُمْ، وَمَا عِنْدِي مَا أَحْمِلُكُمْ ‏"‏‏.‏ فَأُتِيَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِنَهْبِ إِبِلٍ فَسَأَلَ عَنَّا‏.‏ فَقَالَ ‏"‏ أَيْنَ النَّفَرُ الأَشْعَرِيُّونَ ‏"‏‏.‏ فَأَمَرَ لَنَا بِخَمْسِ ذَوْدٍ غُرِّ الذُّرَى، فَلَمَّا انْطَلَقْنَا قُلْنَا مَا صَنَعْنَا حَلَفَ رَسُولُ اللَّهِ صلى الله عليه وسلم لاَ يَحْمِلُنَا وَمَا عِنْدَهُ مَا يَحْمِلُنَا ثُمَّ حَمَلَنَا، تَغَفَّلْنَا رَسُولَ اللَّهِ صلى الله عليه وسلم يَمِينَهُ، وَاللَّهِ لاَ نُفْلِحُ أَبَدًا، فَرَجَعْنَا إِلَيْهِ فَقُلْنَا لَهُ إِنَّا أَتَيْنَاكَ لِتَحْمِلَنَا فَحَلَفْتَ أَنْ لاَ تَحْمِلَنَا، وَمَا عِنْدَكَ مَا تَحْمِلُنَا‏.‏ فَقَالَ ‏"‏ إِنِّي لَسْتُ أَنَا حَمَلْتُكُمْ، وَلَكِنَّ اللَّهَ حَمَلَكُمْ، وَاللَّهِ لاَ أَحْلِفُ عَلَى يَمِينٍ فَأَرَى غَيْرَهَا خَيْرًا مِنْهَا، إِلاَّ أَتَيْتُ الَّذِي هُوَ خَيْرٌ وَتَحَلَّلْتُهَا ‏"‏‏.‏