In Genesis 2:24 the narrator writes that the story of the first man and the first woman coming together is a model for how a man should leave his mother and father, cleave to his wife, and become one flesh. Tomorrow my younger brother is getting married. I am getting married in August. I am wondering to what extent should one “leave” behind their family nucleus?
There are some who make the mistake of simply merging their spouse into their family as an equal while not making the spouse a priority. There are others who forget they ever had a family of origin. For those who are already married, how did you find the balance if you did?
the archives near Emmaus 
Great question. In the ANE when a couple married they often stayed with the family both physically and relationally. Notice Isaac for example. Whatever leaving and cleaving meant, it was not separation from one's family of origin, at least for the son.
Here are a couple of other comments I received via Facebook:
(1) Frances said: imo, the first year of marriage is an unique time where the leaving and cleaving needs to be the most apparent; you're setting a precedent for the rest of your lives. even though you no doubt have had to manage spending family time together before marriage, getting married suddenly means that you have to make decisions that factor in both people as well as the desires of their family, friends, and community. yikes! the biggest lesson for me was that matt and i had the opportunity to build new traditions and patterns as well as keep some of the old. even old family traditions change when a new person is added. the point is that you get to choose how this will work.
(2)Lisa said: Dr. Bev Wiens talks about this in the Human Sexuality class at Western Seminary. She says there is a pattern in life about leaving and cleaving that is really modeled after Jesus. We are born and we cleave to our parents. Then when we marry we leave and cleave to our spouse. Eventually we pass on and leave this life. But there is also a cleaving pattern similar to this in Jesus' life. He was with the Father during the beginning of time (cleaving). For the sake of fulfilling the law and saving us, he left His father to live on earth as a man (leave). He was born and cleaved to his earthly parents. Then he began his ministry and left home. He cleaved to His Father. Eventually he died and is now with the Father (cleaving). Someday he will return so that we may cleave to Him forever!
Charles,
Good point. I thought of that. So there must be something else to it. The pastor who did my brother's wedding said it referred to primary loyalty and honor, not love and location.