Follow set can never contain $\epsilon$ entry. If u derive derive FOLLOW set property, then u can found out, why it cannot contain.
First of all, where we use a FOLLOW set??
When there is a $\epsilon$ entry in FIRST set of LL(1) entry, there we use follow set.
Now, if this NON-TERMINAL doesnot follow by anything, then what do we do?
We just go to that NON-TERMINAL from where it derived, and check it's FOLLOW set
If nothing found , then go from where derived
And , at last if nothing found it returns dolor
$S\rightarrow aS|aA$
$A\rightarrow bB|\epsilon $
$B\rightarrow b$
Now, FIRST of $A$ contains $\epsilon$, and $A$ doesnot FOLLOW by anything,
So, go for FOLLOW of S
Now, FOLLOW of S contains nothing but dolor.
So, $\epsilon$ never possible.