By the way this is a pastor who showed up yesterday to the school awards ceremony in a tight black muscle t shirt. I will never get that most unwelcome inappropriateness out of my head.

In the current ritual, the running assumption is that sufficient hosts ought and therefore will be consecrated at Mass* - something many places actually do manage to do typically - such that recourse to the tabernacle to distribute Communion at that Mass should normally not be necessary, so I would wonder about any interpretation of a rule that hinged (pun intended) on the closing of the tabernacle door.

* Cf.: https://www.usccb.org/prayer-and-worship/the-mass/order-of-mass/liturgy-of-the-eucharist/holy-communion-from-the-tabernacle

Continuous bass,

If people spent more time implementing what the documents say, and less time inventing stuff, the liturgy would be more attractive and less clericalist. You're right to be alarmed.

There is definitely no such liturgical instruction.

Does Fr call it purification?

I remember a couple of priests who'd insist on purifying the vessels after Mass (in one case leaving it to laymen, alas) -- saying (in both cases) that one doesn't wash the dishes in front of the guests at a banquet...

That was long ago. Maybe there are no priests taking that view today.

Don't get too upset about this. Our former Pastor during the last decade of his reign asked that there be only instrumental music during the purifications so that people could pray quietly on their own---a precious rarity in the New Mass---rather than a hymn or motet. I didn't necessarily like the idea at the time, but I acquiesced, and it grew on me, and I appreciated it. I continued the practice to our current pastor, until the past year to so, when I've been experimenting with different arrangements of music during communion to try to keep everyone happy, including doing a "big hymn" at this point. But I've come full circle again, and am now only playing soft instrumental music after communion. We had the Bishop for Confirmation this past Sunday (Pentecost), and his rules for Mass with the Bishop include the instruction that there should be silence after Communion during the purification of the vessels: no singing and no instrumental music. So that's what we did: I have to say that I liked it. So, now I have been still playing after Communion, but much less, allowing a larger gap of silence at that time, and I may cut out the music there all together. I suppose in my old age (36) I am appreciating silence more.

So, again, don't lose sleep over this: just do what he says, it may take some getting used to, and some rearranging of music on your part, but, I think, you will find it to be a good thing.

Continuousbass,

It is sensible to say, "active participation includes listening, and listening must include some silence," so there's nothing in principle wrong with having instruments play (unless it's Lent, or the instruments are played by people who have no idea what they're doing, or the music is execrable in itself) and other voices rest, but there's also no mandate: Commandment #11: there shall be no human voices, but there must be instruments, when the tabernacle closes.

Come again?

Continuous bass, I think the singers need instructions direct from the pastor, not filtered through the interpretation of a third party; do they stop mid syllable, mid verse, or at a natural break point?

Indeed!

Then I turn to whatever it is to play in this moment, there must be a chant melody which goes along with the quiet prayers that are said? “What has passed our lips as food, O Lord, may we possess in purity of heart, that what has been given to us in time may be our healing for eternity.” Is that still in use?

Is this the clarifying question you asked, or do you mean you asked of your pastor?

Might one inquire how old this pastor is?

Does

a tight black muscle t shirt

answer your question?

No, because bad taste has no age limit.

I recall Cardinal Sarah stating during the 2017 Sacra Liturgia conference in Milan that the choir's singing should end when the distribution of communion is completed in order to allow for silent prayer.

EDIT: It was not taken as a prohibition, but a prudential/liturgical judgment.