I Chronicles 5-6  Chapter 5 deals with the genealogies of Reuben, Gad, and Manasseh, those 3 tribes that settled to the east of the Jordan.  Although Reuben was Jacob's oldest son, he lost the birthright because of his sin against his father.  The birthright was actually given to Joseph, in that each of his sons received a portion of the inheritance ( the promised land).  All of these 3 tribes ended up being carried away by the Assyrians.

Chapter 6 records the genealogy of the tribe of Levi.  Levi had 3 sons, Gershon, Kohath, and Merari.
After the Exodus each of these tribes were assigned specific duties in the service of the sanctuary.  Kohath's son, Amran, was the father of Moses, Aaron, and Miriam.  Aaron and his descendants were set apart for the priesthood.  Also from Kohath's descendants through Amminadab or Izhar , comes Elkanah, the father of Samuel.  So Samuel was a Levite

The descendants of Gershon/Gershom and the descendants of Merari are also given here.  Each group were given cities and land among the other tribes of Israel.  Gershom's sons lived among the tribes of Issachar, Asher, Naphtali, and Manasseh.  Kohath's  sons lived among the tribes of Judah and Manasseh.  The sons of Merari lived among the tribes of Reuben, Gad,  and Zebulun. Others lived among the tribes of Simeon and Benjamin. and some with Ephraim.

Again, these are hard for me to follow.  The names seem to change and reappear in different generations.  Yet, I am reminded again that there is a purpose in these words being recorded here.  There would be a time when the exiled would return to Isarel and a temple rebuilt.  It would be important to know who God's chosen priests and Levites were.  It would be important for each tribe to know where their inheritance was.

Truth - the land of Israel is God's chosen land.  The city of Jerusalem is God's chosen place.  For whatever reason, that only He knows, the descendants of Jacob/Israel will forever be His chosen people.  We are called to pray for the peace of Jerusalem.  We must remain on Israel's side.  For "out of Zion's hills" our Savior will come again.

Father,  You are the God of Abraham, Isaac, and Jacob.  You are the God of Israel and that has not changed.  Bless Your people, Lord.  Open their eyes and ears to hear the good news of Jesus Christ, their Messiah Who reigns forever.  Come Lord Jesus we pray, in Your Name. amen