מדרש על שמות 22:3

1) (Vayikra 19:11) ("You shall not steal, and you shall not deny, and you shall not lie, one to another.") "You shall not steal": What is the intent of this (i.e., the prohibition against stealing has already been stated.) Because it is written in respect to stealing (Shemoth 22:6) "He shall pay double, we know the punishment. Where is the exhortation? (It is here,) "You shall not steal."