Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) relates that Hafsah (may Allah be pleased with her) told me that the Prophet (peace and blessings be upon him) ordered his wives to come out of ihram in the year of the Farewell Hajj. Hafsah (may Allah be pleased with her) said: What prevents you from coming out of ihram? He (peace and blessings be upon him) said: "I have matted my hair (talbid) and garlanded my sacrificial animal, so I will not come out of ihram until I have slaughtered my sacrificial animal."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19616