(Ibid.) "You shall not steal": (Exodus 21:14) "One who steals a man and sells him, etc." tells us of the punishment. Whence the exhortation? "You shall not steal." This is an exhortation against stealing a soul (i.e., kidnapping). You say this, but perhaps it is an exhortation against stealing money. (Leviticus 19:11) "You shall not steal" is an exhortation against stealing money. What, then, must be the meaning of "You shall not steal" (here)? You shall not steal a soul.
Where Is the Explicit Commandment That Forbids the Act
Mekhilta Tractate Bachodesh 8:12