Shalom and thank you for your question. Unfortunately your father’s body underwent cremation and you want to dissuade your mother from asking for the same thing to be done to her body when the time comes.
Obviously the approach will have to be very gentle and tactful. I will present here some of the Halachic (Jewish legal) sources that deal with this subject.
Maimonides (also known by the acronym Rambam – Rabbi Moses ben Maimon) in his work Sefer haMitzvot which lists the Torah sources of the six hundred and thirteen commandments and explains them briefly, says that Postive Mitzva 231 states that burial is an important mitzvah, which holds true for every person, even a person who was sentenced to death by a Torah court (which is not done in our era). In Deuteronomy 21:22 23 it says:”…you shall not leave his corpse on the tree (on which he was hanged) for you shall surely bury him on that day.
Judaism totally forbids cremation of bodies. This is due to the concern of nullifying the above-mentioned positive mitzvah, (there are mitzvahs called positive in the sense that an action must be taken, while a negative mitzvah means
refraining from an act that the Torah forbids,) and there is also the concern of defacement of the human body. Another Halachic concern is that of following the customs of gentiles. Still another concern is showing disbelief in the cardinal premise of Jewish belief, resurrection of the dead.
Sources for the above include:
Responsa , יורה דעה סימן קצד, שו”ת אחיעזר ח”ג סימן עב
מלמד להועיל ח”ב
A renownedTorah scholar of recent generations, Rabbi Chaim Ozer Grodensky, rules explicitly that it is forbidden since a person who fulfills the mitzvah of burial is showing his belief in resurrection of the dead, as mentioned above. He brings additional Halachic sources such as the responsa of the Beit Yitzchak based on יורה דעה ח”ב סימן קנ”ה.
In the Talmud Yerushalmi as explained by the Beit Yitzchak on Tractate Ketubot, the severity of this matter is spoken about.
It is important to understand that the Holy One Blessed be He created our bodies in His image, and it is specifically the body which enables us to come close to G-d, for if we were but a soul, without physical wants and desires, we would be like angels – who cannot change or improve! It is in the merit of the body that we can overcome challenges, as it states in Pirkei Avot “An hour of return to G-d and good deeds (keeping G-d’s commandments) in this world is better than the entire afterlife)”. From this we can see that the body must be given it’s proper respect and be buried in honor, as befits the image of G-d.
For all the above reasons we see why a body should not be cremated, (even if the person requests it) since this is a disgrace to the body which served it’s soul during its lifetime in order to serve G-d.
The Jewish people believe in the resurrection, and thus our separation from our bodies is temporary, and although it is true and clear that people who were burned at the stake because of their Jewishness WILL be resurrected, one who has his body burned is showing that he does not believe in the eternity of the soul, thinking that separation from his body is final G-d forbid.
We pray to soon be privileged to witness the resurrection with the revelation of Moshiach speedily in our day!