2 Kings 4:39

Into the field. The schools of the prophets were probably all situated in rural communities, where the students would have the opportunity to raise their own food and to receive a training in agricultural pursuits (see PP 593; PK 230). Because of the scarcity of food, the students in the prophetic schools were evidently forced to go out in the fields to forage.

Wild vine. The exact type of plant here mentioned has not been positively identified. Some have taken it to refer to a kind of wild cucumber or gourd, having the form of an egg and possessing a bitter taste. When eaten it causes pain and violent purging. The young men may have taken these wild cucumbers for ordinary ones, which were highly prized as food (Num. 11:5). In Palestine is also found a creeping plant known as the colocynth, with small leaves of a light-green color and fruit resembling melons, the effects of which can be fatal. The LXX and the Vulgate take it to be the colocynth.

Knew them not. The fact that a man is a prophet does not give him all knowledge, nor excuse him from exercising every care and precaution. This young man, not knowing the nature of the herbs before him, gathered poison and endangered the lives of all who partook of the fruits of his labors.