It is narrated from Muhammad bin Abdullah bin Harith bin Naufal (may Allah have mercy on him) that he heard Sa’d bin Abi Waqqas and Dahhak bin Qais (may Allah be pleased with them both) discussing Hajj Tamattu’ in the year when Mu’awiyah bin Abi Sufyan (may Allah be pleased with him) came for Hajj. Dahhak said, “Only the one who does not know the law of Allah will perform Hajj Tamattu’.” Sa’d (may Allah be pleased with him) said, “O nephew, you have not spoken well.” Dahhak said, “Indeed, ‘Umar (may Allah be pleased with him) forbade it.” So Sa’d (may Allah be pleased with him) said, “The Messenger of Allah (peace and blessings be upon him) performed Hajj Tamattu’ and we also performed Hajj Tamattu’ with him.”
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 807
Hadith Takhrijاخرجه الترمذي، الحج، باب ماجاء في التمتع (823) ۔ وقال ”صحيح“ والنسائي، مناسك الحج، باب التمتع (2735)۔
It is narrated from Ibn Umar (may Allah be pleased with him) that he said: Performing Umrah before Hajj and offering a sacrifice is more beloved to me than performing Umrah after Hajj in the month of Dhul-Hijjah.
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 808
Hadith Takhrijاسناده صحيح : اخرجه البيهقي : 4 / 345 ۔ وفى المعرفة السنن والآثار له (2704)۔
It is narrated from Ibn Abbas (may Allah be pleased with him) that he was asked, "What do you say about performing Umrah before Hajj, while Allah Almighty says: __QUR_N__?" So Ibn Abbas (may Allah be pleased with him) said, "How do you recite: Is the repayment of debt before the execution of the will, or is the execution of the will before the repayment of debt?" They said, "The execution of the will is before the repayment of debt." He said, "Which of the two will you begin with?" They said, "With the debt (i.e., we will pay the debt first)." He said, "So that is it." Imam Shafi'i (may Allah have mercy on him) said: That is, it is permissible to perform Umrah before Hajj.
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 809
Hadith Takhrijفی اسناده مقال : قال ابن حجر في هشام بن حجير ”صدوق له اوهام“ التقريب : 7288 ـ اخرجه البیهقی (351/4)۔