Kautilya's Arthashastra 5.1.32

5.1.32

tadabhivikhyāpya "rasadau" iti ghātayet //

A sauce-maker or a sweetmeat-maker may request of a seditious minister some sauce and sweetmeat by flattering him--"thou alone art worthy of such things." Having mixed those two things and half a cup of water with poison, he may substitute those things in the luncheon (of the king) outside the city. Having made this event known to the public, the king may put them (the minister and the cook) to death under the plea that they are poisoners.