en_tn/dan/11/06.md

they will make an alliance

The king of the South will make an alliance with the king of the North. This alliance would be a formal agreement that both nations are required to follow. Alternate translation: "the king of the South and the king of the North will promise to work together"

The daughter of the king of the South will come ... to confirm the agreement

The king of the South will give his daughter in marriage to the king of the North. The marriage will confirm the agreement between the two kings.

her arm's strength ... his arm

Here "arm" stands for power. (See: rc://en/ta/man/jit/figs-metaphor)

She will be abandoned

This appears to refer to a plot to kill her and those who made the alliance. This phrase may be expressed in active form. Alternate translation: "They will abandon her" (See: rc://en/ta/man/jit/figs-activepassive)