One of the issues the Dvar Avraham is known for is his many tshuvos addressing the order of precedence when one must perform a milah b’zmanah and milah shelo b’zmanah on the same day. He concludes the milah shelo b’zmanah takes precedence - the milah b’zmanah is done early only because of the din of zerizus, but for the post-8th day baby the father is oiver mitzvas milah “b’chol yom” according to the Rambam, which the D.A. is mechadesh means every single moment of delay (yom=lav davka) is a seperate issur, so it should be done first.
In the context of defending his chiddush the Dvar Avraham cites the recent daf yomi gemara (Rosh haShana 6a) that one is over an issur of bal t’acher for any delay in fulfilling a pledge of tzedaka – since the poor are present and ready to accept the charity, there is no excuse for delay. In a footnote he adds an amazing comment: he heard from R’ Yisrael Meir haKohen of Radin (I guess he was not yet known as the Chofetz Chaim) that if a poor person is invited to eat at one’s home on Friday night, since the seudas Shabbos is a kiyum of mitzvas tzedaka, one is not allowed to sing Shalom Aleichem and zmiros, as delaying the start of the meal would violate the issur of bal t’acher!
I have heard this idea in story form, and dismissed it as mussar or tzidkus. However, the Dvar Avraham held it makes sense l’halacha and was forced to offer a limud zechus on behalf of most of us who he assumes are not makpid on this issue. He suggests that since the poor assume they will be fed in the context of the bal habayis’s own meal, it is as if a set time was designated for the tzedaka, and until that set time is reached there is no issur of bal t’acher.
What a testimony to the sensitivity of true gedolei yisrael not only to every nuance of halacha, but to every nuance of chessed and human kindness.