Verse 49. Heathen - David is here transported beyond himself, and speaks this in special relation to Christ who was to be his seed, and of whom he was an eminent type, and by whom alone this was done. And therefore this is justly applied to him, and to his calling of the Gentiles, Rom. xv, 9.
Verse 50. His king - To the king whom God himself chose and anointed, and to all his posterity; and especially to the Messiah, who is called David's seed, Acts xiii, 23 Rom. i, 3.