Part of the Canon of the Mass, said by the celebrant, after the Second intercession and before the Per Ipsum.
All servers should be kneeling during the Per Quem. The acolyte is standing and pointing the missal for the celebrant.
He joins his hands, and continues:
THROUGH Jesus Christ our Lord, through whom, O Lord, thou dost ever create all these food things; dost sanctify, quicken, bless, and bestow them upon us.