Mutarrif reported:

'Imran b. Husain sent for me during his illness of which he died, and said: I am narrating to you some ahadith which may benefit you after me. If I live you conceal (the fact that these have been transmitted by me), and if I die, then you narrate them if you like (and these are): I am blessed, and bear in mind that the Messenger of Allah (ﷺ) combined Hajj and Umra. Then no verse was revealed in regard to it in the Book of Allah (which abrogated it) and the Messenger of Allah (ﷺ) did not forbid (from doing it). And whatever a person (, Umar) said was out of his personal opinion.
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ قَالَ ابْنُ الْمُثَنَّى حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، عَنْ شُعْبَةَ، عَنْ قَتَادَةَ، عَنْ مُطَرِّفٍ، قَالَ بَعَثَ إِلَىَّ عِمْرَانُ بْنُ حُصَيْنٍ فِي مَرَضِهِ الَّذِي تُوُفِّيَ فِيهِ فَقَالَ إِنِّي كُنْتُ مُحَدِّثَكَ بِأَحَادِيثَ لَعَلَّ اللَّهَ أَنْ يَنْفَعَكَ بِهَا بَعْدِي فَإِنْ عِشْتُ فَاكْتُمْ عَنِّي وَإِنْ مُتُّ فَحَدِّثْ بِهَا إِنْ شِئْتَ إِنَّهُ قَدْ سُلِّمَ عَلَىَّ وَاعْلَمْ أَنَّ نَبِيَّ اللَّهِ صلى الله عليه وسلم قَدْ جَمَعَ بَيْنَ حَجٍّ وَعُمْرَةٍ ثُمَّ لَمْ يَنْزِلْ فِيهَا كِتَابُ اللَّهِ وَلَمْ يَنْهَ عَنْهَا نَبِيُّ اللَّهِ صلى الله عليه وسلم ‏.‏ قَالَ رَجُلٌ فِيهَا بِرَأْيِهِ مَا شَاءَ ‏.‏
Reference : Sahih Muslim 1226 e
In-book reference : Book 15, Hadith 185
USC-MSA web (English) reference : Book 7, Hadith 2828
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