Sunan an-Nasa'i 2738
It was narrated that Abu Musa said:
"I came to the Messenger of Allah when he was in Al-Batha', and he said: 'For what have you entered Ihram?' I said: 'I have entered Ihram for that for which the Proper had entered Ihram,' He said: 'Have you brought a hadi (sacrifical animal)?' I said: 'No.' He said: 'Then circumambulate the House and (perform Sa) between As-Safa and Al-Marwah, then exit Ihram, so I circumambulated the House and (performed Sa i) between As-Safa and Al-Marwah, then went to a woman of my people and she combed and washed my hair, I used to issue Fatwas to the people based on that, during the Khilafah of  Abu Bakr and 'Umar. Then one day during Hajj season a man came to me and said: 'You do not know what the commander of the Believers has introduced concerning the rites. I said: O people, whoever heard our heard our Fatwa, let him not rush to follow it, for the commander of the Believers! Is coming to you, and you should follow him. When he came, I said: O Commander of the Believers! What is this that you have introduced concerning the rites? He said: If we follow the Book of Allah, then Allah, the Mighty and Sublime, says: 'And complete the Hajj and 'Umrah for Allah. And if we follow the sunnah of our Prophet then our Prophet did not exit Ihram until he had slaughtered the Hadi (sacrificial animal) (sahih)
أَخْبَرَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، عَنْ عَبْدِ الرَّحْمَنِ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ قَيْسٍ، وَهُوَ ابْنُ مُسْلِمٍ عَنْ طَارِقِ بْنِ شِهَابٍ، عَنْ أَبِي مُوسَى، قَالَ قَدِمْتُ عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم وَهُوَ بِالْبَطْحَاءِ فَقَالَ ‏"‏ بِمَا أَهْلَلْتَ ‏"‏ ‏.‏ قُلْتُ أَهْلَلْتُ بِإِهْلاَلِ النَّبِيِّ صلى الله عليه وسلم ‏.‏ قَالَ ‏"‏ هَلْ سُقْتَ مِنْ هَدْىٍ ‏"‏ ‏.‏ قُلْتُ لاَ ‏.‏ قَالَ ‏"‏ فَطُفْ بِالْبَيْتِ وَبِالصَّفَا وَالْمَرْوَةِ ثُمَّ حِلَّ ‏"‏ ‏.‏ فَطُفْتُ بِالْبَيْتِ وَبِالصَّفَا وَالْمَرْوَةِ ثُمَّ أَتَيْتُ امْرَأَةً مِنْ قَوْمِي فَمَشَطَتْنِي وَغَسَلَتْ رَأْسِي فَكُنْتُ أُفْتِي النَّاسَ بِذَلِكَ فِي إِمَارَةِ أَبِي بَكْرٍ وَإِمَارَةِ عُمَرَ وَإِنِّي لَقَائِمٌ بِالْمَوْسِمِ إِذْ جَاءَنِي رَجُلٌ فَقَالَ إِنَّكَ لاَ تَدْرِي مَا أَحْدَثَ أَمِيرُ الْمُؤْمِنِينَ فِي شَأْنِ النُّسُكِ ‏.‏ قُلْتُ يَا أَيُّهَا النَّاسُ مَنْ كُنَّا أَفْتَيْنَاهُ بِشَىْءٍ فَلْيَتَّئِدْ فَإِنَّ أَمِيرَ الْمُؤْمِنِينَ قَادِمٌ عَلَيْكُمْ فَائْتَمُّوا بِهِ فَلَمَّا قَدِمَ قُلْتُ يَا أَمِيرَ الْمُؤْمِنِينَ مَا هَذَا الَّذِي أَحْدَثْتَ فِي شَأْنِ النُّسُكِ قَالَ إِنْ نَأْخُذْ بِكِتَابِ اللَّهِ عَزَّ وَجَلَّ فَإِنَّ اللَّهَ عَزَّ وَجَلَّ قَالَ ‏{‏ وَأَتِمُّوا الْحَجَّ وَالْعُمْرَةَ لِلَّهِ ‏}‏ وَإِنْ نَأْخُذْ بِسُنَّةِ نَبِيِّنَا صلى الله عليه وسلم فَإِنَّ نَبِيَّنَا صلى الله عليه وسلم لَمْ يَحِلَّ حَتَّى نَحَرَ الْهَدْىَ ‏.‏