Some initial issues of note: this is one of two passages in which a woman is the primary recipient of the vision of the LORD/Angel of the LORD. It is a special birth narrative comparable to the one of Abram/Sarai, Hannah, perhaps Hagar, and one in which, like Hannah, I think makes an impression on the Jesus birth narratives with the angel's visitations to Mary and then Joseph. But there is so much more to this passage.
Quoting from the RSV:
And there was a certain man of Zorah, of the tribe of Danites, whose name was Manoah; and his wife was barren and had no children. And the angel of the LORD appeared to the woman and said to her, "Behold you are barren and have no children; but you shall conceive and bear a son. Therefore beware, and drink no wine or strong drink, and eat nothing unclean, for lo, you shall conceive and bear a son. No razor shall come upon his head, for the boy shall be a Nazirite to God from birth; and he shall begin to deliver Israel from the hand of the Philistines. (Judges 13:2-5)
For most, the interest of the passage is for the miracle of the birth of Samson, the promised Nazirite. It is for this reason, in fact, that she is commanded not to drink wine or "strong drink," which, as a recent archaeological article argues, just means beer, rather than any birth defects that we, as moderns, associate with drinking alcoholic beverages while pregnant. There is a gendered aspect to this passage. The story starts out with a discussion of Manoah--the male is the named marker. His wife remains unnamed throughout the entire story, yet she is the one who is vouchsafed the initial vision. This is what differentiates this birth narrative from, for example, Sarai's--when the three men come to Abram and Sarai and she laughs--or even Hannah's, in which the communication is decidedly one way--Hannah prays to God, but God does not answer, unless Eli's answer counts as such. And this is what makes this miraculous birth story much closer to the ones in the Gospels. Of course, the Gospel of Luke's Magnificat is based upon Hannah's prayer, but it is in response to a vision from an angel (here Gabriel) giving the message of a miraculous birth: "Do not be afraid, Mary, for you have found favor with God. And behold, you will conceive in your womb and bear a son, and you shall call his name Jesus" (Luke 1:30-31). In Luke, she sees the vision rather than Joseph. In Matthew, however, Mary is just stated to be pregnant by the Holy Spirit and Joseph receives a vision only when he is about to separate from her privately (Matt. 1:18-25). So Mary gets the vision in Luke; Joseph in Matthew. This makes our passage in Judges a little more unique, since both Manoah and his wife receive a vision successively (you can only do this with the gospels by harmonization). Nonetheless, in these two stories we get a vision of an angel giving a message of the miraculous birth, a quite stunning vision, as Manoah's wife says:
Then the woman came and told her husband, "A man of God came to me, and his countenance was like the countenance of the angel of God, very terrible; I did not ask him whence he was, and he did not tell me his name..." (Judges. 13:6-7)
In what follows she repeats the message of the angel to her husband. This passage resembles Genesis 32 in some ways. The figure seen is a "man" of God (Gen. 32:24), its uses "God' rather than "LORD/YHWH" in the dialogue, and there is the issue of the unknown name (Gen. 32:29). Moreover, the "man of God" looks like an "angel of God"; that is, the appearance was terrible. If Ezekiel 1 is any indication with the living creatures/cherubim, these would be frightening. This tradition persists, since the Angel Gabriel has to tell Mary not to be afraid (Luke 1:30), as well as Zechariah (1:12-13) and the shepherds (2:9-10). Angels are supposed to be glorious, frightening, and "terrible." She also did not ask "whence he was," where he came from. Does she doubt the angel's origin with God? He looks like a messenger of God...but was he...
Manoah then entreats God:
O LORD, I pray thee, let the man of God whom thou didst send come again to us, and teach us what we are to do with the boy that will be born. (Judges 13:8)
Manoah's petition is successful; God listens to him. Once again, Manoah's wife is the contact person, however. So, while Manoah can successfully speak to God, God sends his messenger to Manoah's wife.: "and the angel of God came again to the woman as she sat in the field; but Manoah her husband was not with her. And the woman ran in haste and told her husband, 'Behold, the man who came to me the other day has appeared to me.'" (Judges. 13:9-10).
Subsequently, the Manoah comes to the man/angel of God and questions him of how to take care of the boy. The angel/man simply answers: "Of all that I said to the woman let her beware..." and then he repeats what he said to her. The man/angel basically says that his message to Manoah's wife was sufficient. Manoah, it seems, either was looking for more information, or wanted to hear for himself.
The next part is particularly interesting. Manoah asks the "angel of the LORD" to stay and they will prepare a kid for him, offering hospitality. The angel refuses to eat with Manoah and his wife, but instead tells them to offer a burnt offering to the LORD (Judges. 13:15-16). The parenthetical remark is what is initially startling: "For Manoah did not know that he was the angel of the LORD." This presumably explains why the angel refuses to eat with the humans, although this is no obstacle in Gen. 18:1-8. So this raises a question of whom Manoah thought this figure whom his wife described as a "man of God" like the "angel of God" because his appearance was "terrible." Perhaps a lesser angel? Perhaps just a striking prophetic human? Some sort of intermediate being? By using so many terms, this passage perhaps creates a bit of confusion: man, man of God, angel of God, angel of the LORD are all applied to this figure. Why were they willing to follow this figure's orders if they did not know "whence he was" and who he was? Any supernal being will do? There is a similar human/divine slippage also present in the Jacob passage in which the "man" becomes revealed as God. Or perhaps an unfolding revelation of identity.
Much like the Jacob passage, the issue of the name comes up once again:
And Manoah said to the angel of the LORD, "What is your name, so that, when your words come true, we may honor you?" And the angel of the LORD said to him, 'Why do you ask my name, seeing it is wonderful?'" (Judges 13:18)
In both Gen. 32 and here, the man/angel/god(?) refuses to give the name. Here the reason is given that it is wonderful. It is over-awing. It also reveals a bit of Manoah's cautiousness toward the figure: the proof of the pudding is in the eating. He wants to know the name (who is this figure, and where does he come from?) so that after these things come true they can honor him (as man, as angel, as god?). If/when these things come to pass--proving the prophecy/revelation true--they will honor him. There is a tinge of doubt in the conditional.
The next part is quite astonishing. Manoah sets up the altar and takes the kid with a cereal offering. He offers it to the LORD, "to him who works wonders.":
And when the flame went up toward heaven from the altar, the angel of the LORD ascended in the flame of the altar, while Manoah and his wife looked on; and they fell on their faces to the ground. (Judges 13:20)
The angel of God/the LORD uses the flame of the burnt offering as a transportation device--he ascends through the flame of the offering. I cannot think of another biblical source in which an angel ascends through the flames of an offering. If there is a source, I would be happy to hear of it. And this is the proof that Manoah needs. For the first time in the passage, they both fall to the ground with their faces to the ground in a position of reverence. Due to this fiery ascent, they seem to have figured out the whence and who of the angel, and do not need to wait for the birth for proof to honor this figure who is now clearly not a man.
The angel of the LORD appeared no more to Manoah and to his wife. Then Manoah knew that he was the angel of the LORD. And Manoah said to his wife, "We shall surely die, for we have seen God." But his wife said to him, "If the LORD had meant to kill us, he would not have accepted the burnt offering and a cereal offering at our hands, or shown us all these things, or now announced to us such things as these." (Judges 13:21-23)
There is a certain irony in the passage. As long as Manoah doubts and they both do not quite know the identity of the figure, the figure stays. When they intuit that it is the (angel of the) LORD or God (made clear through the fantastic fire-traveling trick), they no longer see the figure. Manoah then picks up the tradition of not being able to see God and live (as seen with Jacob, Moses, Hagar, and most recently with Gideon), but his wife reassures that is not the case. If God was going to kill them, it would cancel the message given. So God has to make exceptions to the rule for the case of revelation (one can't reveal something to someone for a particular purpose and kill them before fulfilling that purpose, even give the fact that one should not be able to see God and live). And, what is more, it is just bad manners: God accepted their offerings, it would be rude to kill them after that.
In all, Manoah's wife is the primary recipient of a vision of God/angel of God/angel of the LORD/ the LORD (they are equivalent in the passage) and the primary interpreter of that message. Manoah himself is there to seek reassurance from the figure (who tells him basically to listen to what he already told his wife), offer some hospitality, and set up the offering, which turns out to be the angel of God/the LORD's transportation home. He offers some doubt as well--as to the figure's identity and, once the identity is intuited, of whether they will live. It is here that his wife, the original recipient of the message, offers reassurance, since the message needs to be fulfilled.
All in all, Manoah and his wife are privileged company because they saw a vision of God (or angel of God). While God often pops in and out in Genesis, God is much more distant in Judges. Only Manoah, his wife, and Gideon are vouchsafed with such a terrible vision.