Shiva Purana
दर्शनेषु च सर्वेषु मतिभेदः प्रदर्श्यते॥ परं वेदान्तिनो नित्यमद्वैतं प्रतिचक्षते॥ ९॥
In all philosophical systems the concept of duality is evident. But the Vedāntins call him eternal and non-dualistic.
english translation
darzaneSu ca sarveSu matibhedaH pradarzyate॥ paraM vedAntino nityamadvaitaM praticakSate॥ 9॥
hk transliteration by Sanscript