Apparently the term “Maundy Thursday” comes from the Latin phrase “mandatum novum” meaning “new commandment.” The reference is to John 13, which features the story of Jesus washing the disciples’ feet, followed by his statement about a new commandment he has given them, to love one another.
We actually reached this passage in my class on the Gospel of John yesterday, and had an interesting discussion about whether this commandment is “new,” and if so, in what sense.
Someone asked a question along these lines on Facebook recently, asking what one piece of evidence in particular persuades people to adopt the view that they do.
There are multiple things that I find particularly indicative. The reference to a dome in Genesis 1 is itself significant. But the point becomes even clearer if one knows other creation stories from the Ancient Near East.