Ahmad bin Salamah (may Allah have mercy on him) said: I asked Muslim bin al-Hajjaj (may Allah have mercy on him) about this hadith of Abu Razin (may Allah be pleased with him), and he said: "I heard Imam Ahmad bin Hanbal (may Allah have mercy on him) say: I do not know of any hadith concerning the obligation of Umrah better or more authentic than this, and no one has narrated it as excellently as Shu'bah (may Allah have mercy on him) did."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 8757