3 Nephi 12

Having now fulfilled the law of Moses, the Savior instructs -

"Think not that I am come to destroy the law or the prophets.  I am not come to destroy but to fulfil;
18 For verily I say unto you, one jot nor one tittle hath not passed away from the law, but in me it hath all been fulfilled.
19 And behold, I have given you the law and the commandments of my Father, that ye shall believe in me, and that ye shall repent of your sins, and come unto me with a broken heart and a contrite spirit.  Behold, ye have the commandments before you, and the law is fulfilled."  (Book of Mormon | 3 Nephi 12:17 - 19)

In my mind, not destroying the law but fulfilling the law is all the righteous commandments are still in place, but those portion of the law pointing to the atonement are now fulfilled.  Meaning, for example, the ten commandments are still valid.

Amulek explained -

"...this is the whole meaning of the law, every whit pointing to that great and last sacrifice; and that great and last sacrifice will be the Son of God, yea, infinite and eternal."  (Book of Mormon | Alma 34:14)