The seven verses are sung or recited before the Magnificat prayer in the ferial Office of the seven days preceeding the vigil of Christmas; so called because all begin with the interjection "O". Boethius (c. 480-524) made reference to them, thereby suggesting their presence at that time.
The opening words are:
attingens a fine usque ad finem,
fortiter suaviterque disponens omnia:
veni ad docendum nos viam prudentiae.
reaching from one end to the other mightily,
and sweetly ordering all things:
Come and teach us the way of prudence.
qui Moysi in igne flammae rubi apparuisti,
et ei in Sina legem dedisti:
who appeared to Moses in the fire of the burning bush
and gave him the law on Sinai:
Come and redeem us with an outstretched arm
super quem continebunt reges os suum,
quem Gentes deprecabuntur:
veni ad liberandum nos, jam noli tardare.
before you kings will shut their mouths,
to you the nations will make their prayer:
Come and deliver us,
and delay no longer
qui aperis, et nemo claudit;
claudis, et nemo aperit:
veni, et educ vinctum de domo carceris,
sedentem in tenebris, et umbra mortis.
you open and no one can shut;
you shut and no one can open:
Come and lead the prisoners from the prison house,
those who dwell in darkness and the shadow of death
veni, et illumina sedentes
in tenebris, et umbra mortis
Come and enlighten those who dwell in darkness and the shadow of death
lapisque angularis, qui facis utraque unum:
veni, et salva hominem,
the cornerstone making both one:
Come and save the human race,
which you fashioned from clay
exspectatio Gentium, et Salvator earum:
veni ad salvandum nos, Domine, Deus noster
the Desire of all nations, and their Salvation:
Come and save us, O Lord our God.