An embedding theorem for a limiting exponent

We consider the function space $B_{p,\theta}^l(\Omega)$ of functions $f(x)$, defined on the domain $\Omega$ of a certain class and characterized by specific differential-difference properties in $L_p(\Omega)$. We prove a theorem on the embedding $B_{p,q}^l\subset\Omega)$ in the case when $l=n/p-n/q>0$ and its generalization for vector $l$, $p$, $q$.