To properly answer this question, first let’s have a look at Samson’s life in general before we examine whether or not his superhuman strength came from his hair.
Manoah was Samson’s father, but for many years, Samson’s mother was childless due barrenness (Judges 13:2). After much prayer, God restored her fertility for the express purpose that she should bear a son who would free the Israelites from Philistine bondage (Judges 1, 5). Manoah and his wife (who is not named) had some specific instructions from God. Not only were they commanded to raise the child as a Nazarite, (Judges 5, 7), the mother was also instructed on what food and drink to avoid during her pregnancy (no alcoholic beverages or unclean foods) (Judges 4, 7, 14). But there was yet one more requirement to become a Nazarite: any man under a Nazarite vow was to never cut any hair on their head.
God blessed Samson as he matured and took his vow seriously, leaving his hair uncut (Judges 13:24 - 25). When he grew to manhood he used his great physical strength to literally wage a one-man war against the brutality of the Philistines. He also served twenty years as one of Israel’s ruling Judges.
But then the temptations of the world began drawing him away from God; and the Philistines, who were humiliated and angered that they were unable to destroy Samson because of his strength, devised a plan using the services of a seductive harlot named Delilah.
All the Philistine leaders agreed to pay her a generous amount of riches to find Samson’s secret as to how they could take him down (Judges 16:5). Delilah used Samson’s weakness for women to discover his secret — and ultimately she learned that the cutting of his hair would cause him to be as any ordinary man.
So was Samson’s strength in the hair itself? NO! Samson’s strength was a part of his vow as a Nazarite and it was the breaking of his vow to God that rendered him physically powerless. Delilah ultimately cut Samson’s hair and the Philistines captured him and blinded him.
But after a time Samson repented and when his hair grew back and his great strength returned, he had his revenge against the Philistines by bringing their temple crashing down on them, ultimately losing his own life in the process.
The breaking of any vow can lead to disatrous results and today one of the most obvious broken vows is the breaking of the marriage vow — destroying families and lives. I’m sure if Samson could do so he would warn us of the danger of taking our vows too lightly.