What does Judges 13:19 mean?

Culture of the Old Testament era included a deep respect for hospitality. After hearing good news from a visitor (Judges 13:2–14), Manoah and his wife offer food (Judges 13:15–18). They don't seem to realize this is not merely a "man of God," but is in fact "the angel of the LORD," almost surely God Himself in a temporary form. This "man" has suggested they offer a goat and other food as a burnt offering, instead.

Manoah and his wife follow a typical practice of their time: using a large rock as a kind of altar. Manoah sacrificed the young goat on the rock. He also includes the grain they would have otherwise used to prepare the meal for a grain offering. This is an offering of celebration and honor for the Lord and his goodness. They offer it all to the "one who works wonders," like the miraculous wonder of giving a child to a formerly barren woman and her husband (Judges 13:24–25).

This is a meaningful moment of worship to Yahweh, the God of Israel, in the book of Judges. Much of the book has focused on Israel's service and worship of the false gods of Canaan and surrounding cultures. Now, in response to God's goodness, two Israelites offer worship to the One True God while standing alongside the "angel of the LORD" Himself. It's a moment of blessing for everyone involved.

The verse ends by stating clearly that both "Manoah and his wife were watching." This seems like an odd detail, but it sets up what happens in the next verse. What occurs is not a misunderstanding or trick of the light—it's a clear supernatural act which undeniably proves the truth of all that's been said (Judges 13:20–21).