In Jewish life, we frequently use physical objects to engage in God’s mitzvot, but while these rituals are transitory, the objects are not. In most cases, we throw out the objects once they are no longer needed.

But what if we cannot bring ourselves to toss aside these items, once sacred, now used up? Surely they still contain some trace of the sacred, and Jewish tradition has suggested that any object used for a sacred task retains a measure of holiness, even after the task has been completed.

It is for that reason that at the end of Sukkot, many of us put aside our lulav branches and let them dry out to be used Erev Pesah as a brush or broom during the search for hametz. And why we zest our etrogs to make citrus cake for a festive meal or stick cloves in them to use for the besamim blessing during havdala. It is not only an adherence to the biblical concept of bal tash’hit, do not waste, but also a meaningful way to extend the influence and joy of the Sukkot festival, which begins this year on September 22, beyond its eight-day duration.

During one night of each festival, before we kindle the Shabbat and Yom Tov candles, we light yortzeit candles to commemorate the departed. On the following night, after the holiday is over and there is nothing left inside the small glass or tin container but a white puddle of wax and the metal holder from the wick, we most likely throw it away with the day’s trash.

Our parents and grandparents, however, would keep the glasses from the yortzeit candles for years. It is true they lived in a different age, one that emphasized the preservation of resources, but they also understood what it meant to preserve memory.

How many of us remember seeing a yortzeit glass on bubbe’s countertop? The images occupy our recollections: A grandmother who had a whole set of orange-juice glasses preserved from years of ritual. A grandfather who always sipped his tea from a yortzeit glass, and the glass used again to store the tea bag for another cup of tea the next day. Many of us have tried to re-create bubbe’s chocolate cake but found it difficult to reproduce the family recipe, lovingly passed along, because for so long the standard Jewish units of measurement were a yortzeit glass of sugar and half a yortzeit glass of flour.

We have all been raised on cakes baked with reminiscence, longing and love and have drunk from glasses filled at once with both loss and life. We have learned from loved ones not to let anything, any memory, go to waste. We have all taken an object or a relationship that brought joy and meaning and extended its influence over the rest of our lives. That is now our lifelong task as we remember those we have loved and lost.