What does Judges 13:5 mean?
"The angel of the LORD," essentially God Himself in human form, has appeared to the formerly barren wife of a man called Manoah. God has given her fantastic news: she will have a son. That news is immediately followed with special instructions. This will be no ordinary boy. The Lord has set him aside to live according to a particular set of vows: as a "Nazarite." Further, the child is to experience the unique life of a Nazirite before he is even born.The word Nazarite means "one separated" or "one consecrated." This is different from the term "Nazarene," which means a person from the town of Nazareth. The law given to Israel allowed any Jewish man or woman to take the "vow of the Nazarite" to set themselves apart to the Lord. This was intended to be voluntary, and only for a limited time (Numbers 6:1–21). Nazarites were required to follow three specific rules: No contact with grapes or any product of grapes, including wine or other alcohol, no haircuts, and no contact with dead bodies.
What God tells Samson's mother (Judges 13:24–25) is something new. Samson would not volunteer to be a Nazarite. God appointed him to this lifestyle before he was even born, and with the intent to keep those vows forever. God's instruction was that Samson never contact alcohol or grape products, starting from the moment that he was conceived. He was not to cut his hair, either, even as a child.
The Lord was setting Samson aside for a unique and special purpose: to begin saving Israel from their oppression under the Philistines (Judges 13:1). From the very beginning, the Lord knew Samson would only start this process. The Philistines would continue to afflict the Israelites until later in the tenure of Samuel (1 Samuel 7:12–14) and would persist as enemies until the time of King David.
As He has in the past (Judges 2:16), the Lord is bringing up a deliverer to save His people from their enemies. This time is different. For the first time, God appoints the deliverer before he is even born. Neither does God wait, apparently, for Israel to cry out for help. God's power and grace are working together for the good of His people.