You shall not kindle any fire throughout your habitations upon the Shabbat day. (Exodus 35:3).
It is impossible to understand the Torah without the detailed explanations of each verse given by God to Moses on Mount Sinai. These elucidations, known as the Oral Torah were passed on from teacher to student until they were redacted by Rebbi Yehudah HaNasi forming the Mishnah around the year 200CE. Later discussions formed the Gemara which was compiled around 300 years later. The process of discussion and application of Jewish law continues to the present day.
The Karaites were a religious sect who only believed in the written Torah and shunned our rabbinic tradition. They famously misread the verse above; instead of understanding it to mean ‘you shall not [actively] kindle any fire … on Shabbat’, they interpreted it to mean ‘you shall not [passively] allow fires to [continue to] burn … on Shabbat.’
This implied that not only would it be prohibited to kindle a fire on Shabbat itself, but that all fires, heating and cooking facilities would have to be switched off before Shabbat. This meant the Karaites spent Shabbat in the cold and dark eating only cold food.
The sages of the Talmud always understood this verse to only prohibit kindling a fire during Shabbat (Shabbat 70a). The Torah therefore permits us to leave candles, heating or cooking facilities on provided they had been lit, switched on or set with a time switch before Shabbat.
Rabbi Moshe Isserlis (d. 1572) adds that eating hot foods for Shabbat lunch is more than just a tradition. He writes that those who refrain from doing so may be suspected of not believing our sages regarding this law (Rema 257:8).
Since cholent can be cooked before Shabbat but left on the stove overnight (it is prohibited to cook on Shabbat itself), it has become a popular food in almost all Jewish communities across the world. Family and guests can not only enjoy one of our most delicious dishes, but assert our faith in the sages and the Oral Torah which are so critical to every aspect of our lives.