The chaplain is at work with the canon, when interrupted by Death.
| The Chaplain|
Alas! Alack! then I perceive well
that death is a harsh business.
May God receive [me](1) favorably.
352 His service I can no longer do.
A canon is a priest who's attached to a cathedral. The canons are so called because they lead a rule bound life, "vita canonica".
| The Canon|
For God, I will require forgiveness.
I am ready when it may please him.
When death comes to seek me out,
356 my blessings will not leave me.
"vueille" (modern French: "veuille") is present subjunctive 1st or 3rd person, so strictly speaking it might as well be the chaplain receiving God, like an Evangelical Christian who accepts Jesus as his personal saviour.
Such a thought, however, is anathema to Catholic dogma, and doesn't make sense, when the chaplain in the next line claims to have done "his service" all life. Therefore I add "me".