Amos 4:9
I have smitten you with blasting and mildew: when your gardens and your vineyards and your fig trees and your olive trees increased, the palmerworm devoured them: yet have ye not returned unto me, saith the LORD. I have smitten you with blasting and mildew: when your gardens and your vineyards and your fig trees and your olive trees increased, the palmerworm devoured them: yet have ye not returned unto me, saith the LORD.
The smiting was blasting and mildew upon the crops, and the palmerworm devouring gardens and vineyards and fig trees and olive trees, even when they increased and flourished, so that the harvest was ruined. Crop diseases and destructive pests, with crop failure, drought and other calamities, were the means of the stroke. Those so smitten were Israel, His chosen church professing His name and calling themselves His children. Yet they despised His law and did not keep His commandments, disregarded His word and neglected His cause, turned to Bethel's false worship and trusted in people and false gods instead of Him, and lived in perversity and injustice and inconstancy, wholly unprepared to meet Him except for punishment for evil deeds.
These afflictions were one of God's repeated punishments and chastisements and acts of displeasure, permitted and sent upon a disobedient people. They were sent in love and long-suffering mingled with justice to reclaim a rebellious people, to turn them back and save them if possible, and to teach them to trust in Him. The recital of His past dealings with them was to force home conviction of sin and of righteousness and of judgment. Despite these losses the people did not return to Him. They continued in a wilful, disobedient, rebellious and stubborn course and refused to repent.
The chastisement divides people into two classes, those led to trust in Him who are cared for and plucked as firebrands from the burning, and those continuing disobedient who are forsaken. It gave individuals opportunity to repent and return before chastisement fell in its severest form upon the nation. When these means failed nothing was left but direst measures and the end, hence the warning to prepare to meet God. God's relation to His church and the world is ever the same in principle.