en_tn/2sa/07/15.md

Yahweh finishes describing his promises to King David through the prophet, Nathan.

But my covenant faithfulness will not leave him

Here "will not leave" uses to two negative statements to make a positive statement. AT: "my covenant faithfulness will remain with him."(See: rc://en/ta/man/translate/figs-litotes)

Your house and kingdom will be confirmed forever before you. Your throne will be established forever.

These two phrases have similar meanings and are combined for emphasis. (See: rc://en/ta/man/translate/figs-parallelism)