I will be the God of all the families.

By referring to all the families of Israel, the Almighty God showed the desire to gather not only the southern kingdom, which was made up of the tribes of Judah and Benjamin, who had been deported to Babylon, but also the northern kingdom, which was made up of the ten tribes that had been formed starting with Abraham and grew because of the twelve sons of Jacob.

In other words, God began the nation through a family and desired His people to live within that formation, which was established by Him.