Psalm 108:9 celebrates David's conquest of Moab, Edom, and Philistia, specific examples of the nations serving him in Psalm 18:43.

Psalm 22:27 speaks of all nations bowing to the LORD, echoing the universal dominion hinted at in Psalm 18:43's 'head of nations'.

Psalm 22:28 affirms that dominion belongs to the LORD, the source of David's being made head of nations in Psalm 18:43.

2 Samuel 5:1-7 records David being anointed king over all Israel, directly fulfilling the 'head of nations' statement in Psalm 18:43.

2 Samuel 8:1-18 records David's conquests over multiple nations, directly illustrating his being made head of nations in Psalm 18:43.

2 Samuel 22:44-46 is the parallel account of David's song, nearly identical wording about being made head of nations and foreigners serving him.

Isaiah 55:5 uses almost identical language: 'nations you do not know will come running to you,' directly paralleling David's experience.

Romans 15:12 quotes Isaiah about the Root of Jesse ruling nations, directly linking David's headship to Christ's messianic reign.

1 Chronicles 18:6 records David's conquest of Aram—the historical event behind this poetic summary.

1 Peter 2:10 describes Gentiles becoming God's people—mirroring David's 'people I did not know' becoming his servants.

2 Samuel 3:1 shows David growing stronger during the civil war, the process leading to his exaltation as head of nations in Psalm 18:43.

2 Samuel 10:1-19 describes David's victory over the Ammonites and Arameans, another instance of nations serving him as in Psalm 18:43.