It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) married while he was in the state of ihram.
Amr said: I told Ibn Shihab the hadith of Abu al-Sha'tha', and he said: Yazid bin al-Asamm told me that the Prophet (peace and blessings be upon him) married while he was not in ihram. Yazid bin al-Asamm has also narrated from Sayyidah Maymunah bint al-Harith (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) married her while he was out of ihram. So the narrations differ concerning his marrying while in ihram. If it is authentic that he (peace and blessings be upon him) married while in ihram, while he (peace and blessings be upon him) himself said: "The one in ihram shall neither marry nor give in marriage," then this is to be understood as something specific to him (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13365