This is "mission appeal" weekend for us, when a priest from a far away place comes and preaches and appeals for prayers and financial support. Because of this, I did not prepare to preach this weekend, as Fr. Visitor would be preaching at all the Masses.
Unfortunately, Fr. Visitor missed his flight this morning, and will not arrive until later on in the evening. This leaves me in a bind for the vigil Mass tonight. Since the day I was ordained deacon, I have not presumed to give a liturgical homily without preparing ahead of time, and I don't intend to start now.
However, I am obligated to offer a homily. (see c. 767 in your Code of Canon Law) So what am I going to do, seeing as I don't want to (1) preach without being prepared or (2) deny the people the homily to which they have a right on Sundays, and thereby (3) commit a mortal sin?
Well, here's my solution: Thanks to my favorite homily helper, the Ancient Christian Commentary on Scripture, (of which I only have the Mark volume so far) the people are going to get a little bit of Augustine's homily on the gospel.