First, the person speaking has changed. In the previous verses, the Lord of hosts has been speaking directly to his people through the prophet. But in Malachi 2:10–15 it is the prophet Malachi who speaks. Second, the topic has changed. In Malachi 2:10–16 the matter of marital unfaithfulness is being addressed.
10 Have we not all one Father? Has not one God created us? Why then are we faithless to one another, profaning the covenant of our fathers?