Abu Dawud Book 27, Hadith Number 4127.

Narated By N/A : Abu Hurairah reported the Apostle of Allah (PBUH) as saying: When one of you puts on sandals, he should put in the right one first, and when he takes them off, he should take off the left one first; so that the right one should be the first one to be put on and the last to be taken out.