Original Latin:

O salutaris hostia, quæ cæli pandis ostium, bella premunt hostilia. Da robur, fer auxilium. Uni trinoque Domino, sit sempiterna gloria, qui vitam sine termino, nobis donet in patria. Amen.

English Translation:

O saving Victim, who opens the door to Heaven, hostile wars press. Give us strength, bear to us aid. To the Lord One in Three, may there be sempiternal glory, may He grant us life without end, in the native land with Him. Amen.

- Text is from the last two verses of hymn “Verbum supernum prodiens”

by Tommaso d’Aquino (1225-1274)