Summary: When these events took place, Samson was in trouble and he knew it. The final chapter of his life concludes with a very significant event. May we learn from Samson: trust God, but don't make the same mistakes he did!
When the events of this story took place, Samson is in the Philistine prison in Gaza (16:21); his head was shaved and he was bound in fetters of bronze (brass, KJV). He was sentenced to grind (grain?) in the prison house. Even worse, he was blind—the Philistines had put out his eyes so that even if he did escape (how?) he could never find his way back to Israel again.
This turn of events must have made the Philistines overjoyed. Samson had slain over 1000 of their men before this time and had caused the destruction of an entire year’s grain crop (chapter 15:3-5). Now they had him, firmly, and they weren’t going to let him go.
Even so, Samson was still a chosen vessel to and for the LORD. His time in prison apparently made him realize how much he had failed. Admittedly, he had committed some awful sins and violated his Nazarite vow at least twice. Even so, he was finding his way back to God. He didn’t know what his last days on earth would be, but he knew that not being right with God was no way to live. He had learned that lesson the hard way.
So, even in prison, even now handicapped and with limited mobility, Samson renewed his commitment to at least his Nazarite vow.
[Judges 16:22, KJV] 22 Howbeit the hair of his head began to grow again after he was shaven.
This one verse links the evil which Delilah and the Philistines had done to Samson with his submission to the LORD. One of the first things Delilah had done was to have Samson’s head shaved (Judges 16:19), which had never happened before. Certainly his strength had nothing whatsoever to do with his hair but it had everything to do with obedience to the LORD. For whatever reason, Samson decided to, and deliberately, let his hair grow again.
The length of time between his head being shaved, the re-growth of his hair, and the events of the final day of his life in the verses to follow, is not known. Perhaps the Philistines were in no hurry, apparently, to end the misery Samson was going through at the time. They left him, bound and blind, grinding grain in Gaza’s prison house. They were content to keep him out of the way.
But that changed, when the Philistines decided to have, basically, a national religious holiday!
[Judges 16:23] Then the lords of the Philistines gathered them together for to offer a great sacrifice unto Dagon their god, and to rejoice: for they said, Our god hath delivered Samson our enemy into our hand. 24 And when the people saw him, they praised their god: for they said, Our god hath delivered into our hands our enemy, and the destroyer of our country, which slew many of us.
The five lords of the Philistines decided to make a great sacrifice to their national god, Dagon. This shows how blind they really were to the True God and His dealings with the human race. Dagon was (obviously) an idol, made by human hands but worshipped by the Philistines for a long time. Paul wrote in Romans 1 how the human race started on a long, downward slide away from knowing God to embracing idols—and worse (Romans 1:18-32).
This may not have always been the case: Abimelech, king of Gerar, spoke with the God of Abraham, calling him “Lord (Gen. 20:3-4)” but we are not told if he was ever a believer in the God of Abraham, or if he worshipped Dagon or any other pagan deity. We could hope Abraham led him to faith in the True God but we do not know.
Yet we do know the Philistines credited an idol, made by human hands, with giving Samson into their hands. Incredible! Did they forget that Delilah sold him to the other Philistines for 5500 pieces of silver (worth, perhaps, a fortune in those days) and made sure he was helpless? Dagon had absolutely nothing to do with having Samson made blind, or fettered, or grinding (grain?) in the Gaza prison house, but the spiritually blinded Philistines simply didn’t get it.
Now notice how cruel they were once they saw Samson. There he was, blinded, fettered, and not having any idea where he was. The Philistines began praising Dagon for all he had done! At least they got part of it right: Samson had indeed destroyed part of their country (the grain harvest, vineyards, and olives around Timnath and maybe elsewhere) and had indeed slain many of the Philistines. He killed 30 in Ashkelon to honor his wager at the wedding feast (14:12-19), then an unspecified number whom he “smote hip and thigh (15:8)”, and 1000 more at Lehi when he used a donkey’s jawbone as a weapon (15:15). An estimated 1100 or so may not seem like much but considering one man, alone, did this, no wonder they sang Dagon’s praises when Samson was finally captured and rendered, basically, unfit for combat!