It is narrated from Imam al-Hasan al-Basri (may Allah have mercy on him) that the Commander of the Believers, Sayyiduna Umar bin al-Khattab (may Allah be pleased with him), firmly intended to forbid Hajj al-Tamattu' (performing Umrah in the months of Hajj and leaving ihram). Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) stood up before him and said: "You do not have this authority, for the Book of Allah, the Mighty and Majestic, has been revealed (with its ruling) concerning it, and we ourselves performed Umrah in this way together with the Messenger of Allah (peace and blessings be upon him)." So upon hearing this, Sayyiduna Umar (may Allah be pleased with him) desisted from his intention.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الحج / 1178
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :رجاله ثقات. » «أخرجه مسند أحمد برقم: 21678، وأخرجه مصنف عبد الرزاق برقم: 1495»