The Messenger of Allah ﷺ combined Hajj and Amra together. No revelation came down forbidding this, nor did the Prophet ﷺ forbid them. Yet a man went on to say about them whatever he wished according to his own opinion.
أخبرنا عمرو بن علي قال حدثنا خالد قال حدثنا شعبة عن قتادة عن مطرف
أن رسول الله ﷺ جمع بين حج وعمرة ثم لم ينزل فيها كتاب ولم ينه عنهما النبي ﷺ قال فيهما رجل برأيه ما شاء
Grading, Muslim narrated it (Hadith 168/1226) - see the previous hadith from the narration of Shuba - and Bukhari narrated it in the Hajj chapter, section on tamattu during the time of the Messenger of Allah, Hadith 1571, from the narration of Qatada, by the same wording. It also appears in Kubra, Hadith 3707.