Sahih al-Bukhari, Hadith 1563 ⓘ
Narrated Marwan bin Al-Hakam: I saw `Uthman and `Ali. `Uthman used to forbid people to perform Hajj-at-Tamattu` and Hajj-al- Qiran (Hajj and `Umra together), and when `Ali saw (this act of `Uthman), he assumed Ihram for Hajj and `Umra together saying, "Lubbaik for `Umra and Hajj," and said, "I will not leave the tradition of the Prophet on the saying of somebody."
حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا غُنْدَرٌ، حَدَّثَنَا شُعْبَةُ، عَنِ الْحَكَمِ، عَنْ عَلِيِّ بْنِ حُسَيْنٍ، عَنْ مَرْوَانَ بْنِ الْحَكَمِ، قَالَ شَهِدْتُ عُثْمَانَ وَعَلِيًّا ـ رضى الله عنهما ـ وَعُثْمَانُ يَنْهَى عَنِ الْمُتْعَةِ وَأَنْ يُجْمَعَ بَيْنَهُمَا. فَلَمَّا رَأَى عَلِيٌّ، أَهَلَّ بِهِمَا لَبَّيْكَ بِعُمْرَةٍ وَحَجَّةٍ قَالَ مَا كُنْتُ لأَدَعَ سُنَّةَ النَّبِيِّ صلى الله عليه وسلم لِقَوْلِ أَحَدٍ.
also referenced under: Book 25, Hadith 49 (In-Book) & Volume 2, Book 26, Hadith 634 (USC-MSA)