In this chapter, Samson is born.
Samson is the most famous of all the judges, and also one of the more tragic figures in the OT.
There are a lot of cool things about this story. First of all, I want to point out the recurring theme of barrenness again. Back in Genesis we were told that Sarah, Rebekah and Rachel were all barren (Gen 11:30, 25:21 and 29:31). Manoah's wife (who is unnamed in this story) is also barren, and like her ancestors, she will also play a pivotal role in Israel's history. This, combined with the angelic visit, strongly suggests that Samson has an inherent greatness, that he has so much potential in his future. This whole story recalls us to the angelic visit to Abraham and Sarah, when the LORD predicted Sarah would give birth to a son who carries on Abraham's family line and the divine promise from Gen 15.
Where the story goes different is that Samson just doesn't stay true to the LORD or follow his destiny. But more on that later.
For now, a second point I want to bring up is that Samson is the first Nazirite in the OT. There are only a few Nazirites in the bible, and Samson is the only person in the bible who is explicitly called a Nazirite. It is implied that Samuel and John the Baptist are Nazirites (1 Samuel 1:11, Luke 1:15), but that's pretty much it. To remind my readers, the Nazirite vow was specified in Num 6 as a special vow of dedication to the LORD, and you see that kind of language of dedication here. The requirements of a Nazirite vow are to avoid grapes and wine of every kind, to avoid shaving your head and to avoid dead bodies. Normally the Nazirite vow is a temporary, personal declaration. It is not required by the law of Moses; it is completely voluntary. Here, Samson is being dedicated as a Nazirite from birth for the rest of his life, before his birth and without his consent.
Samuel and John are also vaguely implied to be Nazirites for life as well (and in similar circumstances: children of barren mothers and John's birth is also predicted by an angel). So every reference to a Nazirite in the bible is to one of these lifetime Nazirites. There are no references to the temporary, seasonal Nazirite vow that is instituted in Num 6.
Samson is expected to live a life of strict dedication, but we can expect that the LORD will grant him corresponding power to free the Israelites from their Philistine oppressors. Even Gideon, the other great judge, did not have this level of dedication. However, the story of Samson's calling reminds me of Gideon because of the sacrificial offering. In Judges 6, Gideon prepares an offering to the LORD, when the angel sets it on fire with his staff and disappears. In this chapter, Manoah offers a sacrifice to the LORD and the angel ascends in the smoke of it and disappears. In both cases, Manoah and Gideon fear they will die from seeing the face of the LORD (v. 22 here and Judges 6:22 for Gideon).
So in all of these ways the story of Gideon is similar to that of Samson, and v. 24 tells us that the LORD blesses Samson. In the next chapter we will discover how Samson responds to his calling. Until now, the story has only been about Samson's parents. Samson himself must accept or reject the path set before him.
The last point I want to address is verses 17-18 when Manoah asks the angel for his name and the angel responds, "why do you ask my name when it is beyond your understanding?" This reminds me of Ex 34 when the LORD passes in front of Moses and proclaims his name. Names are significant in the bible (and to some extent in the real world) because they signify identity. The LORD's name is more than just what he is called, it's also who he is. Ex 33:19 says that "my goodness [will] pass before you, and [I] will proclaim the name of the LORD before you..." This is in response to Moses asking to see the LORD's glory. So the LORD is equating his glory, his goodness and his name all together, along with his grace and compassion (in the rest of the verse). Therefore his name is an expression of his character and attributes, what I call identity.
With all that as the background, the angel is saying, "who I am is too great for you to understand." To Manoah, this seems like a rejection, but to us who have access to the whole bible, I see it as an invitation to seek those truths that define who God is, and by understanding his character and nature we can learn about his name. His name is great and beyond understanding, but it is one of the mysteries of God that we can ponder the unponderable and approach the unapproachable, through the empowerment of the Holy Spirit who lives within believers. That it is God with us who helps us to approach God and learn more about God, which no human strength could ever do alone.