Abu Dawud Book 13, Hadith Number 2939.

Narated By Al-Mustawrid ibn Shaddad : Al-Mustawrid heard the Prophet (PBUH) say: He who acts as an employee for us must get a wife; if he has not a servant, he must get one, and if he has not a dwelling, he must get one. He said that AbuBakr reported: I was told that the Prophet (PBUH) said: He who takes anything else he is unfaithful or thief.