Why did the nations join to slay

Why did the nations join to slay
The Lord's anointed Son?
Why did they cast his laws away,
And tread his gospel down?

The Lord, that sits above the skies,
Derides their rage below;
He speaks with vengeance in his eyes,
And strikes their spirits through.

"I call him my Eternal Son,
And raise him from the dead;
I make my holy hill his throne,
And wide his kingdom spread.

"Ask me, my Son, and then enjoy
The utmost heathen lands:
Thy rod of iron shall destroy
The rebel that withstands."

Be wise, ye rulers of the earth,
Obey th' anointed Lord,
Adore the King of heav'nly birth,
And tremble at his word.

With humble love address his throne;
For if he frown, ye die:
Those are secure, and those alone,
Who on his grace rely.