From Dom Guéranger's The Liturgical Year.
On this same day the whole Church unites in the solemn homage which Milan continues to pay, after a lapse of sixteen centuries, to two valiant witnesses of Christ. ‘Our martyrs, Felix and Nabor,’ says St. Ambrose, ‘are the grain of mustard-seed mentioned in the Gospel. They possessed the good odour of faith, though it did not appear to men; persecution arose, they laid down their arms, and bowed their heads to the sword, and immediately the grace that was hidden within them was shed abroad even to the ends of the world; so that we can now in all truth say of them: Their sound has gone forth into all the earth.'
Let us honour them and ask their intercession by the prayer which the Church addresses to God in commemoration of their glorious combat.
Collect
Præsta, quæsumus, Domine: ut, sicut nos sanctorum Martyrum tuorum Naboris et Felicis natalitia celebranda non deserunt, ita jugiter suffragiis comitentur. Per Dominum.
Grant, we beseech thee, O Lord, that as the festival of thy holy martyrs, Nabor and Felix, returns for us to celebrate, it may always be accompanied by their intercession. Through our Lord, etc.