Its significance, explained in the Golden Legend of James of Voragine, as Englished by William Caxton.
Sequence by Adam of St. Victor:
Qui spem dedit peccatori
Quando Saulum increpavit
Et conversum revocavit
Ad matrem Ecclesiam.
Saulus, cedis et minarum
Spirans adhuc cruentarum
In Christi discipulos,
Impetravit ut ligaret;
Et ligatos cruciaret,
Quem in via Christus stravit,
Lucis sue radio;
Qui consurgens de arena,
Manu tractus aliena,
Flet, jejunat, orat, credit,
Baptizatur; lumen redit
In Paulum convertitur
Saulus predo nostri gregis;
Paulus preco nostra legis
Sic in Paulum vertitur.
Ergo, Paule, doctor gentis,
Vas electum, nostre mentis
Et per tuam nobis precem
Presta vitam, atque necem
Eternam elimina. Amen.
Hope in sinners' bosoms raising,
That they pardon will obtain.
When He Saul severely chided,
And, converted, called and guided
Back to Mother-Church again.
Saul, still threats and slaughter breathing,
With blood-thirsty purpose seething,
'Gainst the Lord's disciples tried,
Powers obtained for apprehending,
And, when bound, with torture rending
Those who served the Crucified.
As he journeyed, Jesus struck him
To the earth, and, to rebuke him,
With His radiance made him blind;
Till, once more his feet regaining.
He, a guiding hand obtaining.
In a lodging is confined.
He laments, fasts, prays, believeth,
Is baptized, his sight receiveth;
Changed to Paul that Saul became
Who had been our flock's oppressor;
Paul, henceforth our law's professor.
Into Paul thus changed his name.
Therefore, Paul, the Gentiles' teacher!
Chosen vessel! as our preacher,
Light on our dark hearts outpour;
And, for us thy prayers employing,
Life for us obtain, destroying
Death that lasteth evermore! Amen.