"Noah was a just man and perfect in his generations, and Noah walked with God" — the same phrase, "walked with God," used of Enoch a few chapters earlier, the man who didn't see death. It's a small marker that Noah belongs to that same rare company. And there's a quiet typological contrast worth holding here: Adam fails in a garden, surrounded by abundance; Noah obeys in a wasteland, under threat of total loss. The first man had every advantage and broke faith; this man has none, and keeps it.
God gives him the plan — gopher wood, three hundred cubits by fifty by thirty, pitch inside and out. Pause on the pitch for a second, because the Hebrew word, kofer, shares its root with kippur — atonement, covering. The ark isn't only a boat; it's sealed the way atonement seals, and you'll meet that root again on the Day of Atonement centuries later. One door. One window. A single point of entry for anyone who wants to survive what's coming — and it's hard not to hear, all the way from this chapter, Jesus's own claim in John ten: "I am the door: by me if any man enter in, he shall be saved." That's not this chapter announcing Jesus outright; it's the pattern this chapter sets that John will later pick up and complete.
And here is where the anchor verse belongs for how the New Testament reads Noah's whole obedience: Hebrews eleven says Noah, "being warned of God of things not seen as yet, moved with fear, prepared an ark to the saving of his house." Not seen as yet — that's the whole point. He built a boat on dry land, over decades, on the strength of a warning about weather no one alive had ever witnessed. Peter goes further in his second letter and calls Noah "a preacher of righteousness" — meaning the hundred-odd years of construction were also, the whole time, a sermon nobody heeded.