Q: At weekday mass, where does the priest get the prayer after Communion? Is it the same as the one used the prior Sunday?
A: It depends on the day. If it is an Ordinary Time weekday, yes, he usually chooses the one from the prior Sunday, but he has a wide variety of options – from the Masses for Various Needs and Occasions, and even from some other Sunday in Ordinary Time. During Lent and Easter, however, and on other specific days such as the Conversion of St. Paul, the prayer is proper to the day.