Dr T. Desmond Alexander is a great writer. He writes a lot on the Pentateuch and biblical theology. His books on OT often cover a biblical theological sweep e.g. From Paradise to the Promised Land: An Introduction to the Pentateuch (1995). He has also written From Eden to the New Jerusalem: An Introduction to Biblical Theology (2008). His newest book from Crossway is The City of God and the Goal of Creation: An Introduction to the Biblical Theology of the City of God (2018). he has also written Exodus (2017) in the Apollos OT Commentary series.
It is from his latest book that the above Crossway's article is adapted. It is written very much like William Dumbrell who wrote about how the Bible began with a garden in the book of Genesis and ends with a garden in the book of Revelation.
For Dr Alexander, the OT begins with the book of Genesis of an elevated garden of Eden and the NT concludes with the book of Revelation with a reference to an elevated city of God, the New Jerusalem. Within these poles lies the story of the exodus event climaxing on Mt Sinai, the elevated place where God meets Moses. this is the place where God requires moral holiness from his people. the requirement to ascend any holy hill is the same: moral holiness (as spelled out in two similar psalms, Pss 15 and 24). We who live between the 2 poles are required to demonstrate moral holiness if we wish to ascend the elevated place to God's presence.
if you are interested to read more, go and grab a copy of The City of God and the Goal of Creation. it will be a wonderful addition to your good reading.
below is another link to an interview he did about his area of passion namely, biblical theology.