Seventh of the O Antiphons.

O Rex Gentium,
et desideratus earum,
lapisque angularis,
qui facis utraque unum:
veni, et salva hominem,
quem de limo formasti.

In English:

O King of Nations,
And the one they desired,
The cornerstone
Who makes both peoples one,
Come and save mankind,
Whom you formed from clay.