God will establish your line forever

Psalm 89:4(God will establish your line forever)

     I will establish your line forever
   and make your throne firm through all generations.

2 Sam 7:12-16(God will establish your throne)

   Your house and your kingdom will endure forever before me^[a]; your throne will be established forever.           

1 Ki 8:16(God will establish his chosen people)

   Since the day I brought my people Israel out of Egypt, I have not chosen a city in any tribe of Israel to have a temple built so that my Name might be there, but I have chosen David to rule my people Israel.

Psalm 132:11-12(God promises David that he will bless his descendants )

  The LORD swore an oath to David, a sure oath he will not revoke:
“One of your own descendants  I will place on your throne.

If your sons keep my covenant and the statutes I teach them,
then their sons will sit on your throne forever and ever.”

 Isa 9:7(God will establish David’s throne with justice and righteousness)

Of the greatness of his government and peace there will be no end.
He will reign on David’s throne and over his kingdom,
establishing and upholding it with justice and righteousness
   from that time on and forever.
The zeal of the LORD Almighty will accomplish this.