In the OT (mainly Leviticus) there are found 613 laws, mostly purity laws, some conduct, etc.
These were fulfilled in the NT by Christ. They no longer apply - we are now able to eat/touch pigs, kosher is no longer an issue, etc. The verse you cite is part of this.
We fall under a new law - the law of Christ, the law of the Gospel. This is the law of love - true caritas.