Sahih Muslim Book 31, Hadith Number 5887.
Chapter : The excellent qualities of ‘Umar (Allah be pleased with him).
Abu Sa’id Khudri reported Allah’s Messenger (may peace be upon him) as saying: While I was asleep I saw people being presented to me (in a dream) and they wore shirts and some of these reached up to the breasts and some even beyond them. Then there happened to pass ‘Umar b. Khattab and his shirt had been trailing. They said: Allah’s Messenger, how do you interpret the dream? He said: (As strength of) faith.