|The statement that the patriarchs – Abraham, Isaac, and Jacob – “are the very chariot” means that there was no distinction between them and the heavenly chariot that Ezekiel described in his prophecy.
They were not just like the chariot, but they were the chariot.
A chariot is a vehicle upon which a rider sits, and upon which he may be seen.
The essence of a chariot, or vehicle, is solely utilitarian; it does not choose where to go but is a vehicle that the rider directs as he wishes.
Ezekiel’s chariot was a vehicle for holiness.
When a person is described as a chariot of holiness, it means that his entire being serves as a vehicle for expressing holiness.
From the perspective of the rider, he is not a happenstance vehicle, but the authentic vehicle – always and wherever he goes.
Rabbi Adin Steinsaltz