As a tongue of fire consumes the stubble and the chaff sinks in flames, the root of those who were unjust and evil would be like decay, and their bud would disappear like dust (Isa. 5:24a). Because God's people rejected the instruction of Jehovah of hosts and despised the speaking of the Holy One of Israel, the anger of Jehovah burned against them, and He stretched out His hand over them and struck them (vv. 24b-25a). The mountains quaked, and the corpses of the people were like garbage in the middle of the street. In spite of all this, Jehovah's anger was not turned away; rather, His hand was still stretched out to chastise them (v. 25b).
Finally, Jehovah lifted up a standard to a distant nation and summoned it to come in a swift, strong, and terrifying way to seize Israel as its prey (5:26-30a). Then one would look upon the land and behold darkness and distress, and the light would be darkened in its clouds (v. 30b). The Babylonians did the very things described in these verses.
According to 2:6, Jehovah abandoned His beloved people, the house of Jacob, because they were full of the customs from the east (the nations). His people had forsaken God's law and instructions given through Moses and picked up many customs from the nations, from the Gentiles.