Hi Gigi
The Sabbath and all of the Commandments (600+ of them) were abolished by the death of Jesus Christ.
A few scriptures you could show your husband :
Rom 7:4,6 - So, my brothers, YOU also were made dead to the Law through the body of the Christ, ...But now that we have been discharged from the Law, because we have died to that by which we were being held fast, that we might be slaves in a new sense by the spirit, and not in the old sense by the written code.
Gal 2:13,14 - Christ by purchase released us from the curse of the Law by becoming a curse instead of us, because it is written: "Accursed is every man hanged upon a stake." The purpose was that the blessing of Abraham might come to be by means of Jesus Christ for the nations, that we might receive the promised spirit through our faith.
Col 2:13,14,17 - [God] made you alive together with him. He kindly forgave us all our trespasses and blotted out the handwritten document against us, which consisted of decrees and which was in opposition to us; and He has taken it out of the way by nailing it on the torture stake. ...for these things are a shadow of the things to come, but the reality belongs to the Christ.
As regards disfellowshipping(shunning, excommunication, etc) the witnesses use the scriptures Rom 16:4, 2Thess 3:14 (though they ignore v.15), and 2John 10,11.
And welcome to the board