The works of Ādi Śaṅkarācārya

Viṣṇusahasranāmastotram

Verse 211

इत्यादिवचनैर्वैष्णवलक्षणस्य एवंप्रकारत्वाच्च हिंसादिरहितेन विष्णोः स्तुतिनमस्कारादि कर्तव्यमिति ।'श्रद्धया देयम् अश्रद्धयादेयम्' 'श्रद्धयाग्निः समिध्यते' इति श्रुतेः, मश्रोत्रियं श्राद्धमधीतमव्रतमदक्षिणं यज्ञमनृत्विजा हुतम् ।

In plain words

Because the true mark of a devotee of Vishnu consists precisely in these qualities, all praise, prostration, and worship offered to Vishnu must be free from violence and malice. This is established by scriptural passages: 'Gifts should be given with faith... fire is kindled with faith.' Offerings made to one unversed in the Veda, rites performed without vows, sacrifices without gifts, and oblations poured by unqualified priests...

Close to the Sanskrit

And because the definition of a devotee of Vishnu is of this very nature through such statements, acts of praise, prostration, etc., toward Vishnu must be performed free from violence and other faults. Based on the Sruti: 'Gift should be given with faith, given without faith', 'The fire is kindled with faith'; an unlearned śrāddha offering, studied without vows, a sacrifice without gifts, and oblations offered by an unqualified priest...