We were sitting with Abu Musa Al-Ash'sari, and as there were ties of friendship and mutual favors between us and his tribe. His meal was presented before him and there was chicken meat in it. Among those who were present there was a man from Bani Taimillah having a red complexion as a non-Arab freed slave, and that man did not approach the meal. Abu Musa said to him, "Come along! I have seen Messenger of Allah ﷺ eating of that (i.e., chicken)." The man said, "I have seen it (chickens) eating something I regarded as dirty, and so I have taken an oath that I shall not eat (its meat) chicken." Abu Musa said, "Come along! I will inform you about it (i.e., your oath). Once we went to Messenger of Allah ﷺ in company with a group of Ash'airiyin, asking him for mounts while he was distributing some camels from the camels of Zakat. (Aiyub said, "I think he said that the Prophet was in an angry mood at the time.") The Prophet ﷺ said, 'By Allah! I will not give you mounts, and I have nothing to mount you on.' After we had left, some camels of booty were brought to Allah's Apostle and he said, "Where are those Ashʿariyin? Where are those Ashʿariyin?" So we went (to him) and he gave us five very fat good-looking camels. We mounted them and went away, and then I said to my companions, 'We went to Messenger of Allah ﷺ to give us mounts, but he took an oath that he would not give us mounts, and then later on he sent for us and gave us mounts, perhaps Messenger of Allah ﷺ forgot his oath. By Allah, we will never be successful, for we have taken advantage of the fact that Messenger of Allah ﷺ forgot to fulfill his oath. So let us return to Messenger of Allah ﷺ to remind him of his oath.' We returned and said, 'O Messenger of Allah ﷺ! We came to you and asked you for mounts, but you took an oath that you would not give us mounts) but later on you gave us mounts, and we thought or considered that you have forgotten your oath.' The Prophet ﷺ said, 'Depart, for Allah has given you Mounts. By Allah, Allah willing, if I take an oath and then later find another thing better than that, I do what is better, and make expiation for the oath.' " (two other narrations through Zahdam as above)  

كُنَّا عِنْدَ أَبِي مُوسَى وَكَانَ بَيْنَنَا وَبَيْنَ هَذَا الْحَىِّ مِنْ جَرْمٍ إِخَاءٌ وَمَعْرُوفٌ قَالَ فَقُدِّمَ طَعَامٌ قَالَ وَقُدِّمَ فِي طَعَامِهِ لَحْمُ دَجَاجٍ قَالَ وَفِي الْقَوْمِ رَجُلٌ مِنْ بَنِي تَيْمِ اللَّهِ أَحْمَرُ كَأَنَّهُ مَوْلًى قَالَ فَلَمْ يَدْنُ فَقَالَ لَهُ أَبُو مُوسَى ادْنُ فَإِنِّي قَدْ رَأَيْتُ رَسُولَ اللَّهِ ﷺ يَأْكُلُ مِنْهُ قَالَ إِنِّي رَأَيْتُهُ يَأْكُلُ شَيْئًا قَذِرْتُهُ فَحَلَفْتُ أَنْ لاَ أَطْعَمَهُ أَبَدًا فَقَالَ ادْنُ أُخْبِرْكَ عَنْ ذَلِكَ أَتَيْنَا رَسُولَ اللَّهِ ﷺ فِي رَهْطٍ مِنَ الأَشْعَرِيِّينَ أَسْتَحْمِلُهُ وَهْوَ يُقْسِمُ نَعَمًا مِنْ نَعَمِ الصَّدَقَةِ قَالَ أَيُّوبُ أَحْسِبُهُ قَالَ وَهْوَ غَضْبَانُ قَالَ وَاللَّهِ لاَ أَحْمِلُكُمْ وَمَا عِنْدِي مَا أَحْمِلُكُمْ قَالَ فَانْطَلَقْنَا فَأُتِيَ رَسُولُ اللَّهِ ﷺ بِنَهْبِ إِبِلٍ فَقِيلَ أَيْنَ هَؤُلاَءِ الأَشْعَرِيُّونَ فَأَتَيْنَا فَأَمَرَ لَنَا بِخَمْسِ ذَوْدٍ غُرِّ الذُّرَى قَالَ فَانْدَفَعْنَا فَقُلْتُ لأَصْحَابِي أَتَيْنَا رَسُولَ اللَّهِ ﷺ نَسْتَحْمِلُهُ فَحَلَفَ أَنْ لاَ يَحْمِلَنَا ثُمَّ أَرْسَلَ إِلَيْنَا فَحَمَلَنَا نَسِيَ رَسُولُ اللَّهِ ﷺ يَمِينَهُ وَاللَّهِ لَئِنْ تَغَفَّلْنَا رَسُولَ اللَّهِ ﷺ يَمِينَهُ لاَ نُفْلِحُ أَبَدًا ارْجِعُوا بِنَا إِلَى رَسُولِ اللَّهِ ﷺ فَلْنُذَكِّرْهُ يَمِينَهُ فَرَجَعْنَا فَقُلْنَا يَا رَسُولَ اللَّهِ أَتَيْنَاكَ نَسْتَحْمِلُكَ فَحَلَفْتَ أَنْ لاَ تَحْمِلَنَا ثُمَّ حَمَلْتَنَا فَظَنَنَّا أَوْ فَعَرَفْنَا أَنَّكَ نَسِيتَ يَمِينَكَ قَالَ انْطَلِقُوا فَإِنَّمَا حَمَلَكُمُ اللَّهُ إِنِّي وَاللَّهِ إِنْ شَاءَ اللَّهُ لاَ أَحْلِفُ عَلَى يَمِينٍ فَأَرَى غَيْرَهَا خَيْرًا مِنْهَا إِلاَّ أَتَيْتُ الَّذِي هُوَ خَيْرٌ وَتَحَلَّلْتُهَا  

Messenger of Allah ﷺ said, "Do not seek to be a ruler, for, if you are given the authority of ruling without your asking for it, then Allah will help you; but if you are given it by your asking, then you will be held responsible for it.”

“And if you take an oath to do something and later on find another thing, better than that, then do what is better and make expiation for your oath."  

قَالَ رَسُولُ اللَّهِ ﷺ: «لاَ تَسْأَلِ الإِمَارَةَ، فَإِنَّكَ إِنْ أُعْطِيتَهَا عَنْ غَيْرِ مَسْأَلَةٍ أُعِنْتَ عَلَيْهَا، وَإِنْ أُعْطِيتَهَا عَنْ مَسْأَلَةٍ وُكِلْتَ إِلَيْهَا.»

«وَإِذَا حَلَفْتَ عَلَى يَمِينٍ فَرَأَيْتَ غَيْرَهَا خَيْرًا مِنْهَا فَأْتِ الَّذِي هُوَ خَيْرٌ وَكَفِّرْ عَنْ يَمِينِكَ.»