तदुभयं रसेन योजयित्वा प्रतिस्वादने तावेवोपयोजयेत् ॥ कZ_०५.१.३१ ॥
tadubhayaṃ rasena yojayitvā pratisvādane tāvevopayojayet
Having mixed both (food and drink) with poison, he should employ those very items for ‘counter-tasting’ (i.e., in the tasting step).
To compromise the verification step itself—turning a safety protocol into a delivery mechanism.