Sahih Muslim , Book 7, Hadith 2829 (USC-MSA) ⓘ
'Imran b. al-Husain (Allah be pleased with him) said: Know well that Allah's Messenger combined 'Hajj and 'Umra, and nothing was revealed in the Book (to abrogate it), and the Messenger of Allah too did not forbid us from (combining) them. And whatever a person said was out of his personal opinion.
وَحَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا عِيسَى بْنُ يُونُسَ، حَدَّثَنَا سَعِيدُ بْنُ أَبِي عَرُوبَةَ، عَنْ قَتَادَةَ، عَنْ مُطَرِّفِ بْنِ عَبْدِ اللَّهِ بْنِ الشِّخِّيرِ، عَنْ عِمْرَانَ بْنِ الْحُصَيْنِ، - رضى الله عنه - قَالَ اعْلَمْ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم جَمَعَ بَيْنَ حَجٍّ وَعُمْرَةٍ ثُمَّ لَمْ يَنْزِلْ فِيهَا كِتَابٌ وَلَمْ يَنْهَنَا عَنْهُمَا رَسُولُ اللَّهِ صلى الله عليه وسلم . قَالَ فِيهَا رَجُلٌ بِرَأْيِهِ مَا شَاءَ.
also referenced under: Book 15, Hadith 186 (In-Book) & Hadith 1226 (Reference)