Isaac's tower

He built a tower on the grave of Avraham our father - Avraham accepted it. They built a tower over the grave of Jacob our father - they also accepted it. We built a tower over the grave of our father Yitzchak - they did not accept it. Repeat and rebuild several times and it collapses and falls...

To this day, there are two towers on the graves of Abraham and Jacob, and there is no tower on Isaac's grave.

Therefore, Isaac was called by the Ishmaelites "El Rayor", meaning "the jealous one". And some call Isaac "the father of the sword."

(Book of Hebron - according to the reader Shmuel ben David)