The tree of knowledge appears at Gen 2:9 and Gen 2:17, and is presumably the tree mentioned at Gen 3:4, 11, 12, and 22. In the Yahwist’s creation account, the tree of knowledge is one of two specific trees that God makes grow in the Garden of Eden. It is the only plant from which the human (Hebrew, ha’adam) is forbidden to eat, on consequence of death.
Both times it appears, the tree of knowledge is modified by the adjectives good (Hebrew, ṭov) and evil (Hebrew, ra‘). But what is this knowledge of good and evil that has been deemed off-limits to humanity? Here are four more common interpretations of what it means to know good and evil.
Sexual knowledge. Eating from the fruit of this tree represents the beginning of sexual desire. The Jewish commentator Ibn Ezra first proposed this view in the Middle Ages, noting that after eating the fruit Adam covered his nakedness and “knew (Hebrew, yada’) his wife Eve, and she conceived and bore Cain” (Gen 4:1). Furthermore, in two other places in the Bible, knowing the distinction between good and evil is an indication of puberty (Deut 1:39, Isa 7:15–16). In the Epic of Gilgamesh, the wild hunter Enkidu becomes “like a god” after a week of exploits with a harlot. Scholars point out that this corresponds to the biblical first human becoming “like one of us” (that is, like a god) in Gen 3:22.
Omniscience. Consuming the tree’s fruit gives the eater knowledge of everything. When an author defines the entirety of something by referring to its extremities, it is known as a merism or merismus. Examples in the Bible are “the heavens and the earth” (Gen 1:1) and “when I sit down and when I rise up” (Ps 139:2), which may be understood as “the entire cosmos” and “all activity,” respectively. When Abraham’s servant asks permission to take Rebekah as Isaac’s wife, Laban and Bethuel respond, “We cannot speak to you anything bad (Hebrew, ra‘) or good (Hebrew, ṭov)” (Gen 24:50). That is, they have nothing to say that would prevent the marriage arrangement.
Moral discernment. In an attempt to flatter king David, the woman of Tekoa praises David for being able to discern good (Hebrew, ṭov) and evil (Hebrew, ra’) (2 Sam 14:17). Likewise, when the Lord appears to Solomon in a dream asking “what I should give you,” the new king requests the ability to discern between good (Hebrew, ṭov) and evil (Hebrew, ra’) (1 Kgs 3:5-9). According to this view, eating of the tree of knowledge offers humans the ability to evaluate moral situations and choose between good and evil.
Divine wisdom. Biblical wisdom literature implores its hearers to “get wisdom” (Prov 16:16; see also Prov 23:23). At the same time, it cautions that some wisdom lies beyond the human prerogative (Job 15:7-9; Prov 30:1-4). Proponents of this view point to the King of Tyre, who was metaphorically expelled from Eden for claiming to be a god (Ezek 28:2, 9, and 13) to have “the mind of a god” (Ezek 28:6). Moreover, in the wisdom tradition, life apart from the fear of God is a path that leads to death (Prov 14:12, Prov 16:25), while the one who delights in the law of the Lord thrives (Ps 1). In this view, true wisdom is found in the recognition that life flows from the fear of the Lord, rather than from self-dependent knowledge.
Since the tree of knowledge only appears explicitly in two verses, there is simply not enough information to know its precise meaning. Despite the compelling arguments for each interpretation, scholars remain divided over which view presents the most persuasive case.