Judges 13:1
And the children of Israel did evil again in the sight of the LORD; and the LORD delivered them into the hand of the Philistines forty years. And the children of Israel did evil again in the sight of the LORD; and the LORD delivered them into the hand of the Philistines forty years.
The doing evil again was widespread apostasy and a general turning from Jehovah. Israel had mingled with the nations around them, adopting their practices and their worship. That course was a continued backsliding even after deliverance from the Ammonites. For that evil the Lord delivered Israel into Philistine power and permitted the Philistines to oppress them for forty years. The power of the oppressor rested more heavily upon the land year by year.
Amid that defection the faithful worshipers of God continued to plead for deliverance. Year after year there was apparently no response and it seemed there was no answer. Yet a few households remained true in that time. Among them was that of Manoah, of the tribe of Dan, at Zorah.
Even in the early years of that oppression God's providence was already preparing help. A son was promised and then born through whom God would begin to deliver Israel. Through that child God designed to humble the power of these mighty foes, the Philistines. God designed that son, Samson, to accomplish a great work for Israel. Therefore at the very outset of his life the utmost care was taken to surround him with the most favorable conditions for physical strength, intellectual vigor, and moral purity.