I saw ʿAli and ʿUthman ؓ between Makkah and Madinah. ʿUthman was telling people not to do tamattuʿ or join them together (Hajj and ‘Umrah, i.e., qiran). When ʿAli ؓ saw that, he entered ihram for both of them together and said: Here I am for ʿUmrah and Hajj together ‘Uthman ؓ said: You see me telling the people not to do that and you do it? He said: I will not give up a Sunnah of the Messenger of Allah ﷺ for the opinion of anyone among the people. (Using translation from Aḥmad 1139)   

عُثْمَانَ وَعَلِيًّا ؓ بَيْنَ مَكَّةَ وَعُثْمَانَ ؓ يَنْهَى عَنِ الْمُتْعَةِ وَأَنْ يَجْمَعَ بَيْنَهُمَا فَلَمَّا رَأَى ذَلِكَ عَلِيٌّ ؓ أَهَلَّ بِهِمَا جَمِيعًا فَقَالَ لَبَّيْكَ بِعُمْرَةٍ وَحَجَّةٍ مَعًا فَقَالَ عُثْمَانُ ؓ تَرَانِي أَنْهَى النَّاسَ عَنْ شَيْءٍ وَأَنْتَ تَفْعَلُهُ فَقَالَ مَا كُنْتُ لِأَدَعُ سُنَّةَ رَسُولِ اللهِ ﷺ لِقَوْلِ أَحَدٍ مِنَ النَّاسِ  

[Machine] "And the other (person) said: Both of them? So I went out as if carrying them on my back until I reached Umar. So I mentioned to him what they said. He said: Indeed, they do not say anything. You have been guided by the tradition of your Prophet ﷺ , the wording of the hadith of Abu Mu'awiyah."  

وَقَالَ الْآخَرُ أَبِهِمَا جَمِيعًا؟ فَخَرَجْتُ كَأَنَّمَا أَحْمِلُهُمَا عَلَى ظَهْرِي حَتَّى قَدِمْتُ عَلَى عُمَرَ ؓ فَذَكَرْتُ لَهُ الَّذِي قَالَا فَقَالَ إِنَّهُمَا لَا يَقُولَانِ شَيْئًا هُدِيتَ لِسُنَّةِ نَبِيِّكَ ﷺ لَفْظُ حَدِيثِ أَبِي مُعَاوِيَةَ