In Genesis, the LORD shuts Noah inside the Ark before the flood begins.
Genesis 7:16 says that Noah, his family, and the animals entered the ark as God had commanded, and then the LORD shut Noah in. This short sentence places the final closing of the vessel under divine action rather than describing Noah or one of his sons fastening the door.
The detail is easy to miss because many retellings focus on construction, animal pairs, and rainfall. It also differs from the common picture of Noah personally closing a large door after everyone boards. The Genesis wording gives the moment a protective and decisive role at the boundary between the old world and the flood.
The title “the LORD” reflects the English convention used in many Bible translations for the Hebrew divine name YHWH. Other translations may render the line with “the Lord,” but the referent is the same in this passage.