Here's a little more to add to what Shimei has said....
There is no single thing to look at for this topic but here are a couple things to look at to determine if there really is a separation between moral and symbolic laws and if so, how to determine what is "moral" and what is "symbolic"......
1) I'd say the vast majority of Christians believes in absolute morality. If absolute morals exist, then anything that God would tell some people to do but tell others they don't have to wouldn't be considered a "moral" law. One example of this is what Shimei has given already, circumcision. If you'd like more examples just ask.
2) A few scriptures....
Col 2:13 And you, being dead in the deviations and the uncircumcision of your flesh, He made alive together with Him, having forgiven you all the deviations,
Col 2:14 blotting out the handwriting in the ordinances against us, which was contrary to us, even He has taken it out of the midst, nailing it to the cross;
Col 2:15 having stripped the rulers and the authorities, He made a show of them in public, triumphing over them in it.
Col 2:16 Then do not let anyone judge you in eating, or in drinking, or in part of a feast, or of a new moon, or of sabbaths,
Col 2:17 which are a shadow of coming things, but the body is of Christ.
Right there gives a few broad areas that could be considered "symbolic", i.e. food, drink, festivals/holidays, sabbaths.
Those are a couple things, but those can only take you so far. There are a variety of laws in the Mosaic Law that can't easily be categorized and it seems (to me) that if a particular law is hard then it's just put in the symbolic category. One example of that is the one about a woman grabbing a man's junk. No one wants to say that should be put into practice today (the law, not the grabbing. :chuckle: ) but I don't think I've ever seen a great explanation of what that symbolized. Maybe someone has a reasonable one though. :idunno: