Verse 20

यथा शीतोष्णयोर्नित्यं परस्परविरुद्धयोः ।न संभवति संबन्धो राम देहात्मनोस्तथा

In plain words

Just as no connection is possible between cold and heat, ever mutually opposed, so, Rāma, it is between body and Self.