His book on threshold (or cornerstone) covenants - The threshold covenant - while an excellent exposition of what the concept is, never really delves into the spiritual ramifications of what happens when it goes wrong. It does not mention the constriction and wasting so many people experience when they try to come into their calling. The sorts of things I have documented in God's Pageantry: The Threshold Guardians and the Covenant Defender.
Threshold covenants are everywhere in Scripture. And overlooked almost everywhere.
To understand what people thought about them through the ages, it's necessary to pick likely books and delve into them. Which is why I picked Jewish Folklore. It seemed a "likely" book.
And it did indeed turn out to have occasional information about threshold covenants (not that it called them that).
It mentions, for instance (p 31), the custom of painting a broad blue frame around doors and windows to avert the 'evil eye'. (Mentioned by Paul in Galatians 3:1, so the 'evil eye' is not an extra-Biblical concept.)
On the same page, it mentions also a curious activity which goes back to the days of the Judges - that of young people dancing, singing and merry-making on, of all days, the Day of Atonement.
It mentions the tohu of Genesis 1:2 - the green band that surrounds the world. (pg 96)
On pg 227, it mentions qodom, 'foot', the sacrifice on the threshold made for the bride as she enters the groom's house for the first time.
On pg 228, it details how this differs from the Muslim practice of a bride crossing a threshold.
On pg 289, it mentions how water is poured on the threshold at the birth of a child.
Of course, there's lots more in this book than just threshold information. It just happens that this was the reason I read the book and what I happened to be looking for most.