It is narrated from Sa'id bin al-Musayyib (may Allah have mercy on him) that he said: "I do not know anyone at all among the people who, after the Messenger of Allah (peace and blessings be upon him), was more learned and of deeper knowledge than Sayyiduna Umar bin al-Khattab (may Allah be pleased with him)."
Imam Ishaq bin Rahwayh narrated it in his Musnad, and its chain is sahih (authentic).
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب المناقب / 3890
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناده صحيح » «انفرد به المصنف من هذا الطريق»