Sometimes it's just a sound, sometimes a particular sequence of sounds associated with a text setting.
Simply mentioning the text was enough to bring back the most vivid moment: Purcell setting the words "sharpness of death" in a Te Deum.
It would have been even more closely interwoven with my sense of the day had there been a convincing sweetness against which to contrast it. But, as it was not the usual voices singing in the choir, their tuning was less than sweet. Curious, how a cappella singing makes its own terms.