Behold, I [am] against them that prophesy false dreams, saith the Lord,.... And not true ones, such as the Lord spoke in to his prophets, and which they communicated from him to his people; see Nu 12:6;and do tell them, and cause my people to err by their lies, and by their lightness; by the false doctrines and prophecies which they delivered, and by their loose and disorderly lives which they led; so that they debauched the principles of the people by the former, and their practices by the latter.
Kimchi interprets the word translated "lightness" of lightness of their knowledge; as if it was through the shallowness of their judgments, and want of capacity in teaching, that the people were made to err by their false doctrines.
The Targum interprets it of their temerity or rashness; and Schultens , from the use of the word in the Arabic language, explains it of their pride and false glorying;yet I sent them not, nor commanded them; wherefore they lied, and acted a vainglorious part, when they pretended they were sent by him, and had their orders from him what they should say; see Jer 23:21;therefore they shall not profit this people at all, saith the Lord; so far from it, that they did them a great deal of hurt by their lies and flatteries; seducing them from the ways and worship of God, and leading them on in such as would issue in their destruction, and did.
Animadv. in Job. p.