Scholars are agreed that the Hebrew word ‘adashah refers to the lentil Lens culinaris (formerly known as Lens esculenta). The Arabic word ‘adas, as well as several references in post-biblical Hebrew, confirm this identification, as does the Greek Septuagint. Seeds found in excavations dating to the sixth or seventh millennium B.C. show that the lentil is one of the first species to be cultivated by humans. In those excavations lentils are often found together with seeds of wheat and barley.

The lentil is a low-branched plant with a weak stem. It has tendrils, like pumpkins and squashes, and pinkish flowers that develop into a pod like a bean. The pod is very short with only one seed inside, about the size of a small pea. In one type of lentil the pea is reddish brown, hence the reference to “red” stew in Genesis 25:30. The pods are often in pairs or sets of three. In the Holy Land lentils grow in the cold season (November-March).

In Ezekiel 4:9 the strange bread, made from six kinds of grains and legumes including lentils, was probably intended to show that food would become scarce and that the people would have to eat whatever they could find. The lentil is typically used in soups and stews, as it was when Jacob used it to trick his brother Esau into giving up his rights as the firstborn son. Lentils were among the foodstuffs brought to David by local people when he was pursued by Absalom.

 Lentils are now widespread in Asia, India, and North Africa. In places where they are not known, we suggest using the word for a local type of bean rather than a transliteration. However, in Ezekiel 4:9 “beans” are also mentioned, so a possible rendering for “beans and lentils” is “different kinds of beans.” In Genesis 25:34 a generic expression for “pottage of lentils” would be appropriate, such as “bean soup,” “bean stew,” or “vegetable soup.” If a transliteration from a major language is desired, consider Arabic adas; French cristallin, lentille; Spanish lenteja; Portuguese lentilha; and Swahili adesi.

Source: Each According to its Kind: Plants and Trees in the Bible (UBS Helps for Translators)