In the Udyoga Parva of the Mahabharata, Krishna comes to Hastinapura as the envoy of the Pandavas. Duryodhana invites him to a feast. Krishna declines. “Envoys, O king, eat and accept worship only after the success of their missions,” he says, in the Ganguli translation.
Duryodhana presses him. Krishna answers: “One taketh another’s food when one is in distress. At present, however, O king, thou hast not inspired love in me by any act of thine.” He goes to the house of Vidura and eats there.