Sunan An-Nasai, Chapter: The Book of Purification

"Thumamah bin Uthal Al-Hanafi went to fetch some water that was near the Masjid and performed Ghusl, then he entered the Masjid and said: 'Ashhadu an la ila ha ill-Allah wa ashhadu anna Muhammad (SAW)an 'abduhu wa rasuluh (I bear witness that there is none worthy of worship except Allah and I bear witness that Muhammad (SAW) is His slave and Messenger), O Muhammad (SAW), by Allah! There was no face on the face of the Earth that was more hateful to me than your face, but now your face has become the most beloved of all faces to me. Your cavalry captured me and I want to perform 'Umrah. What do you think? The Prophet (saw) gave him glad tidings and told him to perform 'Umrah." (Sahih)