It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) married Sayyidah Maymunah (may Allah be pleased with her) while he was in the state of ihram during a journey.
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 2393
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد حسن