I've long been puzzled by rabbinic references to foods that do not seem on the surface to be accurate. What do I mean? For example, lentils, which rabbis of old considered a suitable food to serve a mourner because they are "round."
But lentils are not round. Quite the contrary, they are almost flat with an oval shape, and have been from time immemorial. Look at this bit of lentil triva:
The optical lens is so named after the lentil (Latin: lens), whose shape it resembles.[1] The same applies also to Greek language, where the word φακός means lens and φακή means lentil. In the Persian language, a lens is referred to as adasi where adas means lentil. In Hebrew, a lens is known as adasha (plural adashot) and adash (plural adashim) means lentil. In Turkish, mercek means lens and mercimek means lentil. In French the word lentille is used to mean either lens or lentil. In Serbian, word sočivo and in Croatian leća, means both lentil and lens.
So what gives? Were rabbis simply playing fast and loose with reality in order to darshan Ya'akov's red (lentil) stew as the mourning meal for his family on his grandfather Avraham's passing, and thereby make Eisav look bad?
Maybe not.
Last week I had Indian food that had been imported from India rather than locally prepared. The lentils were round, almost like large peas. This is an unusual strain of lentil, now found mostly in India. Perhaps there was a time when these lentils were also found in Israel. Whether that time was concurrent with Ya'akov and Eisav or concurrent with Rabbi Yochanan and Yossi HaGlili is another matter, as is the possibility these round lentils were found in Babylonia during the time of Ravina and Rav Ashi but never in Israel during the past 5000 years.
This has implications for halacha because of the common measurements used in Jewish law – the size of a lentil and half a lentil. Why? Because the Indian round lentils are larger than our lentils by as much as two times.
So what is the real history of the lentil as it applies to Jewish law and thought? This, as we say, needs looking into. Perhaps some of you can do that and report back what you find.