Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates from Hafsah (may Allah be pleased with her) that in the year of the Farewell Hajj, the Prophet (peace and blessings be upon him) ordered his wives to leave the state of ihram.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19688