All the choice parts for Hashem
The Gerrer Rebbe, R Avraham Mordechai, owned a pair of tefillin that had been written by R Moshe of Peshevorsk. These were very prestigious tefillin indeed.
The Rebbe wore them only on erev Yom Kippur, apparently considering himself unworthy of donning them on any other day.
Once, a boy came to him and said that he had no tefillin. The Gerrer Rebbe
took the precious tefillin and handed them to the boy. Seeing the boy put
on the tefillin written by R Moshe of Peshevorsk, the Rebbes sons asked
their father for an explanation.
The Torah says, all the choice parts for Hashem, the Rebbe explained. The Rambam says that just as we must offer up to Hashem the choicest parts of the
sacrifice, so, too, when it comes to the mitzvah of giving tzedakah to the poor, we must give only of the best!