Sahih Muslim Book 024, Hadith Number 5233.
Chapter : Pertaining to the wearing of sandals (or shoes).
Abu Razin reported: Abu Huraira came to us and he struck his forehead with his hand and said: Behold I you talk amongst yourself that I attribute wrongly to Allah's Messenger (may peace be upon him) (certain things) in order to guide you to the right path. In such a case, I would myself go astray. Listen. I bear testimony to the fact that I heard Allah's Messenger (may peace be upon him) saying: When the thong of any one of you is broken, he should not walk in the second one until he has got it repaired. This hadith has been reported on the authority of Abu Huraira with a different chain of transmitters.