Even if you haven't read the Bible, you may have seen the one verse from it that mentions "millet" on a brand of sprouted bread and cereal named after that verse: Ezekiel 4:9.

"Take thou also unto thee wheat, and barley, and beans, and lentils, and millet, and spelt, and put them in one vessel, and make thee bread thereof; according to the number of the days that thou shalt lie upon thy side, even three hundred and ninety days, shalt thou eat thereof." Ezekiel 4:9 (ASV)/1

But do we know what millet it was exactly?

The Hebrew is דֹּחִן (do'chan), which more than one source on the Bible say is Panicum miliaceum (proso or broomcorn millet). One of those sources, the authoritative McClintock and Strong Biblical Cyclopedia is among those commentaries./2

That source also notes the Arabic cognate, دُخْن (duḵn), which it says also refers to P. miliaceum. However, Wehr and Cowan's authoritative A Dictionary of Modern Written Arabic (3rd ed., 1976) defines the term as pearl millet, i.e., Pennisetum glaucum./3

Both the Hebrew and Arabic words come from roots that also denote smoke. McClintock and Strong see the connection with proso as being "the dark-green or smoky color of the leaf." However, one should also note that the grains of pearl millet typically have a greyish hue, that might be called a smoky color as well.

Another source on the Bible, says that the Arabic word is used "to describe two different kinds of millet" (which it does not specify)./4 That might remove the ambiguity in favor of the Hebrew word meaning P. miliaceum - if perhaps the two millets in Arabic are proso and pearl.

However, it would be useful to consult work of historians and ethnobotanists on the dissemination of these two crops in the ancient Middle East - one coming from China and the other from West Africa.

A shallow dive on the latter suggestion ...

It's hard from researching online to get any clear answer, and I'm under no illusion that "doing my own research" on the internet about common names for millets in ancient languages would refute the conclusions of Biblical scholars. However, having worked along the boundaries of domain expertise, where understandable errors can be made and overlooked, I would not be astonished if a valid case could be made for pearl millet in the Book of Ezekiel.

There has been research and discussion about how the African-origin millets - pearl millet, sorghum, and finger millet - made their way to India./5 It is also known that on the one hand, pearl millet was in Egypt fairly early, and that proso was in Sudanese Nubia for a time, even though there's apparently no evidence for it in Egypt or Mesopotamia. While proso disseminated across Eurasia to Europe, did it also follow a sea-coast route from Asia to Nubia (the reverse of what has been posited for African millets to India)?

All of this, by the way, before the time of the Book of Ezekiel. Could proso have become the or an established millet in the Middle East in the time of Ezekiel? Keep in mind that its cultivation in Nubia did not endure. What of pearl millet in the region during this period? 

Anyway, lots of questions.

Don