Question: What does it mean to build an altar of whole stones?
Answer: Whole stones represent the stony heart (Lev ha even). Stones are egoistic properties that the children of Israel took, and without changing anything in them, they built altars, thus raising to the property of bestowal, love. That is, they corrected their hearts of stone.
Question: Does it mean that exactly what is not processed is taken?
Answer: No, but the simplest, the primitive egoistic desire is taken in order to build holiness over it.
A processed stone means that you are already trying to apply and adjust the ego in a way that suits you.
From KabTV’s “Secrets of the Eternal Book” 7/19/21